Beyond Stonehenge, Treasures in the Landscape - Stonehenge Access All Areas, Ep 9

The Sarsen Transport Routes - A Least Cost Model

A terrain model you can argue with. Open this to understand this post: https://sarsenroute.netlify.app/ 

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Fifty of the fifty-two sarsens at Stonehenge came from West Woods, near Marlborough. That was settled in 2020 by matching their chemistry to the source. It leaves the interesting part open: how thirty-tonne stones travelled 25 km south, across the Vale of Pewsey, to the monument.

Several routes have been proposed over the years, mine among them. None has field evidence behind it. So rather than argue for another line on a map, I set out to ask a narrower question:

If the only things that mattered were the shape of the ground, what it is made of, and the water on it — where would the cheapest road run?

The answer is not a line. It is a corridor: 37 km², about 5% of the landscape searched. Within that band the terrain barely cares which way you go.

Doing it blind

I am one of the people with a published route, which is a problem. So the method was written down and committed before any data arrived, and the published proposals — including my own — were sealed in a file that stayed closed until the result was frozen. No proposed route, mine included, is scored anywhere in the paper.

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https://sarsenroute.netlify.app/ 

What the ground says

Four things came out that I did not expect.

The vale crossings are on sand, not clay. National geological mapping shows the Vale of Pewsey floor as one great smear of Gault clay and greensand. Zoom in to 1:50,000 and the five places where roads actually cross the vale turn out to sit on greensand benches — firm ground — with the real clay lying to the west, between Stert and Urchfont. Across all 360 model runs, not one metre of route touches Gault. The clay is real. Nothing goes near it.

There are only five crossings in eleven kilometres of vale — and adding every footpath and bridleway to the metalled roads adds no new ones. The same five places. When footpaths don't create new crossings, the crossings are being fixed by the ground.

Better data made a question harder, not easier. Two ways down off the Marlborough Downs, 2.8 km apart, are what the model has to choose between. At 50 m resolution they differ by 1.7% in cost. At 1 m, measuring the gentlest line the ground allows, they differ by 1.2 percentage points of gradient. More resolution made them more alike. Huish is not steep ground.

What separates them isn't the slope. It's use. One descent — Walkers Hill — carries a worn way running continuously from 219 m down to 140 m at a steady 6%, with the dished profile of a holloway. Andrews and Dury drew a road down it in 1773 and none down the other. The Huish face has a narrow farm track and nothing else.

Andrews and Dury's map of 1773

The bit I find most interesting

With no thumb on the scale, the model preferred the unused descent.

That isn't a bug, it's a bias — and I suspect it's general. A 50 m terrain model averages a scarp face. A smooth, unwalked hillside averages nicely. A hillside with a deep worn track in it averages badly. So the model kept choosing the easier- looking slope precisely because nobody had ever used it.

Feed in the evidence that one descent was used and the other wasn't, and it moves. But the model needed telling. It could not work that out from the ground alone.

What it can't do

A least-cost path is not a route. It knows nothing about ownership, tradition, season, weather or who you were allowed to walk past. It says what the ground permits, not what people did.

And it doesn't reproduce my own route. I think the stones came down Walkers Hill and crossed the vale beside Honey Street, on a low rise you can see on the ground. The rise is real — 1 m laser survey and the terrain model both find it, standing a couple of metres above the ground either side. What isn't shown is that it was made, or that anyone used it. The model doesn't go that way, and I've left that disagreement in the paper rather than tidy it out. A model that agreed with me would be worth less.

Have a go yourself

The model is online as a set of sliders: sarsenroute.netlify.app

Three hundred and sixty routes, pre-solved. Turn up the fear of hills, or of wet feet, or of river crossings, and watch the corridor move. There is no correct setting — that's the point. The route is a function of what you think a hauling party was most afraid of, and the tool makes that dependence visible instead of hiding it behind one confident line.

The full technical paper, with the method, the data and the things that went wrong, is on https://www.researchgate.net/publication/413532460_Modelling_the_sarsen_transport_route_West_Woods_to_Stonehenge_A_blind_least-cost_analysis_over_layered_open_data and https://www.academia.edu/172184320/Modelling_the_sarsen_transport_route_West_Woods_to_Stonehenge_A_blind_least_cost_analysis_over_layered_open_data.

Data: OS Terrain 50, BGS Geology, Environment Agency LIDAR (all Open Government Licence), OpenStreetMap. Analysis and drafting with Claude and Grok; the errors are mine.

Avebury 3D Fly Through

A 3D topographical fly through of the Avebury Landscape - https://avebury-3d-flythru.netlify.app/ . Play with it and get back to me with comments. It is schematic and only shows a sample of the monuments, but importantly it shows Silbury in relation to its neighbouring hills.

All built with Open Source Data so is freely shareable.

The various periods which you can switch between in the 3d model.

Click to expand

Why We Still Don’t Know Where Britain’s “Missing” Neolithic Ancestry Came From

I’m not a geneticist by trade. I’m an amateur who got stuck on a question that the big Beaker papers leave half-open, and then spent a long time trying to close it with public data only—the same call sets, tables and annotations everyone else can download.

The question sounds small. After the great ancestry turnover in Britain around 2450 BC, English Chalcolithic–Early Bronze Age genomes still carry roughly 7–9% ancestry that looks Middle/Late Neolithic-related. Where did that residue come from?

• Local British farmers absorbed into incoming communities?

• Or continental people who were already mixed before they arrived?

Those are different pasts. One implies survival and incorporation on this island. The other implies the “British-looking” fraction was already baked into migrant groups. Group averages hide the difference. You need to know whether almost everyone carries a thin layer, or whether a few people carry a lot and most carry none.

I thought public IBD, f-statistics, Y/mt labels, and the shape of published ancestry estimates would settle it. They don’t. What I think I have produced—and why I’m bothering to post—is a clearer map of why they don’t, and therefore where the problem has to be solved next. Not a funding pitch. A diagnosis.

What I actually found

1. The residue looks population-wide, not a mosaic of survivors.

On the Booth × Olalde overlap (n = 28), once one extreme individual (I2462) is set aside, the group is statistically homogeneous at about 7.15%. Between-person scatter is small; models where only a minority carry the component and everyone else carries none are excluded. Booth’s gradual rise through time reproduces—and it is a rise in everyone. That is a real result, and as far as I can tell it hasn’t been stated this way with a scripted dispersion bound behind it.

It still doesn’t tell you provenance. An already-mixed import is uniform from day one. A local pulse absorbed over ten to fifteen generations is uniform by the time we sample Early Bronze Age people. Same snapshot. Different histories.

2. The “trace it home” instruments fail on public products.

Long shared segments (IBD), allele-frequency contrasts aimed at British private drift, and uniparental “insular” screens all break under ordinary audits: leave-one-out, site pruning, shared-depth truncation, positive controls. The discriminating information—rare variants, fine Y structure, long-segment continuity at time depth—isn’t reliably in the 1240k / AADR-shaped data we all use. Sometimes the burial still holds it; the assay and the label conventions don’t.

3. Those are two different kinds of failure.

Three instruments fail because information was discarded (capture + harmonisation). The residue-shape instrument fails because information was erased (admixture before these people lived). Collapsing both into “we need more aDNA” is how you waste the next decade.

I also built a Sardinian re-imputation instrument to ask whether public IBD nulls are partly old pipelines rather than ascertainment. It validates within poles; the decisive cross-pole test is specified and not run due to the constraint of my available resources.

Where and how to solve it (not “who should fund it”)

If the goal is provenance of that 7–9%, the map is annoyingly specific:

A. Where the assay threw the information away

Hold the same individuals and change the data product: shotgun (or denser) sequencing → modern imputation → rare-variant / fine-lineage / IBD methods. Especially useful where the same person already exists in both capture call sets and shotgun releases (a clean ascertainment test). Published library-quality metrics for the people I’d prioritise suggest this is practical for most of that set, not all—some look too thin on public annotation alone.

B. Where time erased the information

Don’t keep sequencing well-sampled Early Bronze Age individuals expecting residue structure to reappear. Sample closer to the transition—Chalcolithic / earliest Bronze Age—where an absorbed local pulse might still show heterogeneity. That is a dating-and-excavation problem as much as a sequencing problem.

C. What not to confuse with a solution

More Beaker genomes won’t answer this. Ireland isn’t a free continuity control across the same interval. Collapsing Y strings to “I2” and calling it local doesn’t survive a shared-depth check. And a homogeneous ~7% background is evidence about structure, not a passport stamp for “British Neolithic survival.”

Why post this as an amateur?

Because the literature often states the residue, then slides past the provenance question—or treats every failed test as “low power” instead of “wrong information class.” I’m not claiming a final β. I’m claiming a usable negative architecture: four instruments, two kinds of limit, and a concrete split in where the next honest attempt has to go.

The draft paper: 

https://www.academia.edu/171955479/The_last_seven_per_cent_a_known_unknown_in_the_British_Beaker_transition_Four_instruments_two_kinds_of_limit_why_the_provenance_of_Neolithic_ancestry_in_Early_Bronze_Age_Britain_cannot_be_resolved_on_published_data

https://www.researchgate.net/publication/412356174_The_last_seven_per_cent_a_known_unknown_in_the_British_Beaker_transition 

Full deposit (pre-registrations, results, code, audit trail):

https://doi.org/10.5281/zenodo.21995822 (https://zenodo.org/records/21995822)

https://github.com/TimDaw37/british-neolithic-ibd-audit-supplement

If I’ve got something wrong in the genetics, I want to hear it. If the diagnosis is roughly right, the next useful work isn’t another average—it’s either denser data on the right people, or older people on the right dates.

───

• “Uniform at 7% is a result. It just isn’t a provenance result.”

• “Some missing answers are missing chips. Some are missing centuries.”

• “I’m an amateur. The deposit is public. Please break it if you can.”

The Plain Truth About Wildfires

 

Chalk downland has three available trajectories, and only one preserves the habitat as designated. It can be grazed to a standard. It can burn. Or it can be under-grazed, in which case succession returns it to coarse grass, scrub and ultimately wood — though the route to wood runs through a long phase of high fire hazard, so the third option tends to collapse into the second. The largest chalk grassland in north-west Europe has been demonstrating what the second produces for the better part of a century.

The habitat is semi-natural, a product of clearance and sustained grazing rather than undisturbed succession. The sheep-and-fold system held the downs open by grazing the hill and folding the flock on valley arable, exporting nutrients from hill to field year on year. That impoverishment is the basis of the botanical interest: low herbs persist because nothing vigorous can establish to shade them out. The habitat therefore has no equilibrium of its own.

Prescriptions have shifted over the last two decades from a uniformly short sward with zero tolerance of scrub toward structural mosaics, on the sound grounds that short turf serves a narrow suite of species and little else. Marsh fritillary and Duke of Burgundy, both notified features of Salisbury Plain, require tall tussocky vegetation and successional scrub margins. Structural diversity, however, means standing dead material — upright brome and tor-grass, unpalatable past early summer, accumulating a dense basal layer annually, and favoured by nitrogen deposition into a system whose interest depends on being nutrient-poor. In spring the taller sward retains moisture; in drought the same material cures into fuel.

The uncontrolled experiment

Salisbury Plain Training Area holds roughly 390 square kilometres of chalk under military control since 1897, with the SSSI, SAC and SPA covering 19,690 hectares and notified for twenty-five features. Grazing is logistically constrained: stock must be enclosed and moved around firing schedules, and research on the Plain has largely had to work on ungrazed swards. In the impact areas the constraint is absolute. Unexploded ordnance excludes the fire service from range danger areas, and the standing position on impact-area fires is to suspend firing, monitor, and let them burn out; water cannot be dropped directly, since low flying risks detonating ordnance by heat. Figures obtained under Freedom of Information put wildfires linked to MoD training sites at 1,178 between 2020 and August 2025.

Fire as a management agent

Natural England's Integrated Site Assessment of the SSSI (2014–15) records that wildfires in the Central Impact Area help produce species-rich swards in places by removing thatch build-up, and that Centre for Ecology & Hydrology work there has shown pronounced cyclicity in devil's-bit scabious — the marsh fritillary's foodplant. The feedback is straightforward: undergrazing accumulates dead material, dead material carries fire, fire removes it, herbs recover. The revegetating shell craters produce short-sward grassland supporting rare plants including early gentian, and are thought to act as fire refugia for marsh fritillary. The ordnance provides the firebreaks.

Fire and grazing are not equivalent instruments. Grass fires remove biomass without discrimination — work on grassland invertebrates on the Plain characterised burning and mowing as indiscriminate in what they take, against the selective defoliation a grazing animal provides. Fire takes tussocks and anthills along with the thatch, and anthills do not resprout, nor do the twelve nationally rare and scarce bryophytes for which the Plain is notified, nor the lichens. Woody growth, by contrast, is only top-killed: hawthorn and blackthorn survive at the root and return.

What the regime selects for

The same assessment describes the fires as an unreliable and potentially hazardous management tool that possibly promotes tor-grass. It records tor-grass as having increased substantially on the Central Impact Area since the mid-1990s, with no control available other than grazing and vehicle compaction along tracks; a CEH aerial-photograph study commissioned alongside it found the extent of Brachypodium rupestre significantly expanded there over the preceding decade. Natural England classes tor-grass as a negative indicator species.

Tor-grass is rhizomatous, unpalatable, litter-forming and a vigorous resprouter — a grass optimised for precisely this regime. The trajectory in the impact area is therefore not toward scrub but toward a fire-maintained monoculture: structurally open, botanically impoverished, and self-sustaining, since each burn returns the ground to the species best placed to reoccupy it.

This is the grass–fire feedback operating as expected. Fire is a weapon of grasses, implicated in the expansion of open grassy biomes through the late Miocene, but a weapon for grasses carrying the requisite traits — and on the chalk the grass holding it is the one under suppression. The prairie and steppe analogy fails for a further reason: those systems are grassland because the climate will not carry closed forest. The Wessex chalk sits within the woodland envelope, which is why the downs require management at all, and lightning in oceanic Britain largely arrives with rain. The chalk flora carries no fire-adapted traits of consequence — no serotiny, no fire-cued germination. Against the 2002 condition assessment, the proportion of grassland parcels passing all mandatory attributes rose from 43% to 62%, an improvement Natural England attributes principally to scrub management rather than to any natural process.

Prescription, not abandonment

The term for the third trajectory matters. Withdrawal of grazing on the chalk is not usually abandonment in the economic sense; it is frequently prescribed. On the Plain, grazing runs through Farm Management Plans with some forty-five tenant farmers, which require long grass margins, specify maximum rather than minimum stocking levels, and in special-restriction areas limit grazing to a mapped proportion of the area per year. The basic stocking rate on the chalk grassland is 0.3 livestock units per hectare per year. Natural England's own assessment notes that the plans emphasise avoiding over-grazing but do not adequately emphasise avoiding under-grazing or litter removal — and it identified under-grazing as the principal threat to the chalk grassland, flagged on 83 of the 282 parcels surveyed.

The standing fuel load is therefore not simply what happens when farming retreats. It is in substantial part a consequence of prescription, and graziers reducing numbers are often doing what they have been asked to do.

The transitional hazard

Reduced grazing is no safer a route than fire, for structural reasons. Succession from open sward to closed canopy passes through a phase carrying both fuel types at once: a continuous fine fuel bed of rank grass and litter, and above it establishing hawthorn, blackthorn and dogwood holding fine dead material. Fine fuel governs ignition and rate of spread; woody fuel governs intensity and residence time. The transition holds the maximum of both, and the hazard falls away only at canopy closure, when shading suppresses the sward and fine fuel continuity breaks. On chalk that window opens once scrub establishment is underway, which is the phase under-grazed downland and much recent rewilding now occupies.

The general finding is well supported: withdrawal of grazing drives woody encroachment, encroachment increases flammable biomass, and increased fuel load raises both wildfire probability and intensity, with herbivore grazing identified as the corresponding mitigation.

The choice

Grazing to a standard maintains the notified interest, at cost and with continual attention. Under-grazing leads to woodland, but only across two decades of elevated hazard during which the transition is liable to be interrupted — and interruption returns the ground to the fire-adapted grass. Fire holds it open indefinitely and without expense, and converts it to something structurally similar and botanically far poorer.

Fire is not a third route to preserving chalk grassland but a third outcome, and the one that arrives by default. That it arrives partly by prescription is the part worth examining.

How big a pit was 10067?

 

When the A344 was lifted in 2013–14, Wessex Archaeology examined what was left beneath the road bed. Seven and a half metres north of the Heel Stone they found a feature, 10067, surviving 0.06 m deep, three finger widths. It took some skill to notice it at all, and there was not a lot to record. Powell et al. interpreted it as a shallow tree-throw hollow.

The interesting question is not what survives but what was cut. Nobody digs a hole six centimetres deep. Whatever 10067 was, what was found is the very bottom of it, and how big a pit it was depends entirely on how far below the contemporary ground surface that bottom sits.

Hawley's photograph, 10067 is the dark mark just this side of the motor car

10067 is marked with a dark mark this side of the Heelstone

The road makes that hard to establish. Until it was tarmacked in 1935, a chalk road was maintained by scarifying, watering and rolling. That takes out the ruts and gives a remarkably smooth surface, at the cost of removing chalk each time, so roads of this kind sank slowly. The early photographs show a dark patch where 10067 lies — a soft spot in the road surface, which is what you would expect from a deep feature with looser fill compacting under traffic. The looser top surface was removed before the road was tarmacked taking it down to a firm surface. On top of all that, the corridor was machine-stripped for the watching brief. The surface Powell recorded from is not the surface 10067 was dug from.

The 2013 excavation - 10067 is marked with the metal stakes, note the section revealed at the bank.

Levels

Two Ordnance Survey benchmarks are cut into the Heel Stone. The lower one is a broad arrow with the levelled bar above it, about 0.1 m above the turf, published at 100.70 m OD. Pitts tied his 1979–80 levels to it, so his sections can be read directly against the stone.

That gives a run of comparable figures for the entrance zone:

• Pit 97 — about 1 m deep, base 1.60 m below the mark, so about 99.1 m OD. Pitts's fig. 7 is contoured in centimetres below the benchmark, which is why this one is solid.
• Heel Stone ditch — cut about 0.8 m into the chalk, base just touching below 99 m (Pitts fig. 8).
• Avenue ditches — 0.75–0.80 m deep, base near 99 m, and consistent between the Vatchers, Pitts and Powell.

Three features, two campaigns, all bottoming out around the same horizon.

Pitt's Fig. 7 - Stonehole 97

Pitt's Fig. 8  Heelstone Ditch - note 99m OD mark

Pitt's Fig. 13 - Avenue Ditch - note 99m OD mark

Click to enlarge.

Where 10067 sits

Not, unfortunately, from the published levels. Powell's GPS heights do not reconcile with the earlier work. He records the natural at the edge of the Heel Stone ditch, inside the road-line, at 102.13 m — that is 1.43 m above a benchmark cut just above ground level at the stone a few metres away. It is not merely an offset, it is the wrong way round: the road ran below the ground at the stone, not above it. Powell notes the inconsistency and leaves it unresolved. So do I.

Which leaves the photographs. The verge in my photograph of the stripped corridor shows the old road in section with the turf line above it, and the perimeter fence for scale — standard chain-link, probably1.8 m. Reading the drop against that, the surface Powell was working from lies something like 1.2 m below the turf beside the Heel Stone, so around 99.4–99.5 m OD. The base of 10067, a further 0.06 m down, comes out somewhere in the region of 99.3–99.4 m.

That is a reconstruction from photographs, not a survey, and it is worth a couple of tens of centimetres either way. But it is enough for the point. The base of 10067 sits close to the level at which Pit 97, the Heel Stone ditch and the Avenue ditches all stop. And it was cut from a surface a metre or so above where it was found, which makes it a substantial pit rather than a scrape.

So what was it?

I am not going to claim it is definitely a stone-hole. The evidence will not carry that, and even if we knew the actual OD of the surface it was found in, and the archive might be able to reveal that, we would still only be able to improve its comparison to the other pits.

But a pit of that size, seven and a half metres north of the Heel Stone, bottoming at much the same depth as 97, is not obviously a tree throw either. It sits in a zone already full of holes nobody can explain: 97, B, C, the A holes, the Heel Stone's own ditch. Stones put up and taken away? The Heel Stone shifted about like a pawn from one hole to the next? Whatever was going on here, 10067 and the other holes deserve deeper scrutiny.

Rows around the Heel Stone

Stone and timber settings, linear arrangements, and the limits of the archaeological record north-east of Stonehenge

Introduction

The north-eastern approach to Stonehenge is the most frequently viewed and least systematically excavated part of the monument. The solstitial axis, the proximal Avenue, and the Heel Stone all occupy a narrow wedge of chalk that also contains a dense concentration of recorded features: approximately a dozen stone positions, more than sixty post-holes, at least one sarsen working floor, dwelling pits, and four earthworks. Despite this density, the ground has never been examined as a research excavation. Every intervention since Hawley’s 1923 cuttings has been salvage work conducted ahead of infrastructure.

This paper sets out the recorded features, presents measurements from published plans that identify a previously unremarked linear arrangement of stone-holes, and examines one feature from the 2014–15 road-removal works whose published interpretation remains under-determined.

 

Hawley’s plan with 97 and 10067 added

 

History of investigation

The A344 constrained all work from the 1760s until 2013. Hawley (1923) cut across the Avenue but stopped approximately 3 m short of the Heel Stone. Subsequent interventions (Atkinson et al. 1953–56; Vatcher 1968; Pitts 1979–80) were linear trenches cut for services. The combined 1979–80 exposure amounted to a ribbon roughly 50 m long and 0.5–0.65 m wide. The 2014–15 mitigation following road removal remained a watching brief with targeted slots rather than an area excavation (Powell et al. 2019).

Recorded features

Stone positions include the standing Heel Stone (96), the recumbent Slaughter Stone (95), and emptied settings: Stonehole 97, Stonehole B (WA 3606), Stonehole C (WA 3609), Stoneholes D–F at the entrance, WA 3603 (Hawley’s chip-dump crater), WA 3610 and 3611, and an unlabelled feature near WA 3721.

Timber settings fall into two distinct groups. Across the causeway Hawley recorded some fifty-three post-holes arranged in six roughly parallel rows; these are comparatively slight features that he interpreted as the remains of a palisade. In addition, three substantially larger post-holes were found immediately adjacent to the Heel Stone. These measured 43, 35 and 32 inches deep (approximately 1.09 m, 0.89 m and 0.81 m), were spaced roughly six feet apart in a straight line and showed traces of a fourth. The Avenue bank had been thrown over them, and at least one appears to lie within the zone later occupied by the Heel Stone ditch. They are visible on Plate X of the 1925 report. Despite their size, comparable in depth to several of the stone settings in the same area, these larger post-holes have received almost no subsequent attention.

Earthworks consist of the Avenue ditches and banks, the enclosure-ditch terminals, and the Heel Stone ditch (approximately 1.2 m deep, with an antler pick sealed beneath silt).

Hawley’s 1923 cutting

Hawley cut across the Avenue beside the Heel Stone in a strip perhaps thirty feet wide. Within it he recorded a dump of 3,760 sarsen chips overlying a bed of sarsen sand, accompanied by five small hammerstones but no large mauls (WA 3617/3618). Some fragments retained the natural crust of a boulder; others were reddened by burning. His diary notes that the debris lay beneath the Avenue bank, placing the working before the construction of the earthwork.

Partly beneath the chip dump lay a crater-shaped hole 5 ft across and 4 ft 6 in deep (WA 3603), with one or two smaller holes beside it that Hawley interpreted as footings for a timber frame used to move a stone (WA 3604, 3605). Half-way across the cutting was a second, rougher hole with irregular sides, 3 ft 9 in to 4 ft 6 in across and of similar depth (WA 3606, Stonehole B), surrounded by hard grey sarsen but without a chip dump. From it a trench approximately 9 ft wide with sloping sides (WA 3607) ran towards the Heel Stone, backfilled with chips of every stone type present on the site. Further west lay a third large hole (WA 3609, Stonehole C).

The same cutting produced the line of large post-holes described above and, around the Heel Stone itself, a ditch 4 ft deep and 3½ ft wide. An antler pick lay on the bottom beneath eighteen inches of silt that contained no stone chips; chips appeared only in the higher fills.

  

Hawley Plate X - click to enlarge. I think hole 10067 shows as a dark mark as does the further avenue ditch in the unsealed road.

Geometry from published plans

Distances and bearings measured from the Heel Stone on Cleal et al. (1995, fig. 156), with an estimated uncertainty of ±0.3 m, are as follows:

Feature	Distance (m)	Bearing (°)
Stonehole 97	3.8	336
WA 3605	6.4	198
WA 3604	6.8	192
WA 3603	7.6	185
WA 3606 (Stonehole B)	8.3	253
WA 3611	9.0	194
WA 3610	9.5	191
WA 3609 (Stonehole C)	16.2	237

 

Stoneholes 97, B and C form an approximately straight, evenly spaced line (spacings 8.7 m and 8.5 m; segment bearings 227° and 222°). Looking north-east along the same line yields bearings of approximately 42–47°. This places the row in the general sector of the horizon occupied by both the Neolithic summer solstice sunrise (approximately 49.5–50°) and the major northern lunar standstill moonrise (approximately 40°), but several degrees from either extreme. It is therefore not a close match for the principal solstitial axis of the monument or for the major lunar limit.

Stonehole 97 lies 0.8 m off the line through B and C, within measurement error given its truncated outline. The Heel Stone itself projects 4.2 m south-east of this line. WA 3603, 3610 and 3611 form a separate cluster offset from the axis.

A second, shorter alignment of Stoneholes D, E and the Slaughter Stone socket lies near the entrance, oriented roughly perpendicular to the axial row, with the Slaughter Stone socket falling on the extended 97–B–C line within error.

Implications

The long-standing debate has treated Stonehole 97 as an isolated feature—either the original socket of the Heel Stone or the setting of a paired companion. The measured geometry indicates that 97 is the north-eastern member of a row of three emptied settings. The simplest reading is therefore that it held one of those three stones, not the Heel Stone.

The moved-stone hypothesis (Hawley 1928; later variants placing the Heel Stone originally in 97) requires the stone to have been extracted from a member of the row and re-set 4 m beside it. It also conflicts with Hawley’s own 1925 assessment that WA 3606 was too small for the Heel Stone—an objection he did not reconcile when he later proposed that the stone had come from that hole.

The alternative reading, that the Heel Stone is a survivor of an earlier group of unshaped sarsens (Hawley 1925; Pitts 1982), is strengthened by the presence of an axial row, a transverse group at the entrance, and additional emptied pits, one of them sealed by a dressing floor and the Avenue bank.

Portable XRF data indicate that the Heel Stone shares its chemistry with the majority of the other sarsens and is consistent with a West Woods source (Nash et al.). Its undressed state is therefore a deliberate choice rather than evidence of local origin.

The 2014–15 works and feature 10067

Powell et al. (2019) confirmed that the Avenue ditches survive to depths comparable with sections outside the former road line and that periglacial features are present both within and beyond it. Road construction does not appear to have caused wholesale truncation of deeper features.

A shallow hollow 0.06 m deep (context 10067), located within the Avenue immediately north of the Heel Stone ditch, was interpreted as the base of a tree-throw. No section, fill description or morphological argument is published. The feature lies on the previously inaccessible northern side of the stone. Approximate measurement from the published plan places it roughly on the projected line of the 97–B–C row, but the data are too imprecise for secure geometric conclusions.

Absolute levels recorded in 2014–15 sit more than a metre above the traditional Heel Stone benchmark values used by Pitts (100.70 m OD, Newlyn datum) and, apparently, by earlier excavators. Hawley’s Fourth Report cites the upper benchmark (B.M. 332.5 ft = 101.346 m, Liverpool datum). The discrepancy remains unresolved in the published literature and prevents direct comparison of absolute heights across campaigns.

Whether 10067 represents a truncated artificial socket or a natural hollow cannot be determined from the published record. The critical missing datum is the depth of the road cut at that specific point, which exists in the project archive.

Conclusions

Measurement of published plans identifies an evenly spaced axial row of three emptied stone-holes (97, B and C), with the Heel Stone standing 4 m off the line. Stonehole 97 is therefore better understood as one end of that row rather than as the unique former position or partner of the Heel Stone.

Feature 10067 remains under-determined. Both the geometric arrangement and the status of 10067 can be tested by reference to existing archives. The principal constraint is not the absence of evidence but the limited extent to which the evidence already recovered has been examined.

References

Cleal, R.M.J., Walker, K.E. and Montague, R. 1995. Stonehenge in its Landscape: Twentieth-century Excavations. English Heritage.

Hawley, W. 1925. Report on the excavations at Stonehenge during the season of 1923. Antiquaries Journal 5, 21–50.

Hawley, W. 1928. Report on the excavations at Stonehenge during 1925 and 1926. Antiquaries Journal 8, 149–176.

Nash, D.J., Ciborowski, T.J.R., Ullyott, J.S., Pearson, M.P., Darvill, T., Greaney, S., Maniatis, G. and Whitaker, K.A. 2020. Origins of the sarsen megaliths at Stonehenge. Science Advances 6, eabc0133.

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