Geological implications

Our inference that the Cuckoo Stone and Tor Stone probably originated in the West Woods area directly challenges the suggestion made by Richards (Reference Richards and Parker2020) that both stones were either already situated at, or close to, their source locations when they were monumentalised. There is, however, a potential counter argument that would support Richards’ view: rather than the two stones being moved from West Woods, could it be that large sarsen boulders with a geochemistry similar to those at West Woods were already present in the Stonehenge landscape near the sites where the two stones were raised? This is a difficult question to answer conclusively without extensive sampling and geochemical analysis. However, were it to be correct, it would require the convergence of five geological factors:

1. a) Assuming that the silicification of sarsen stones in Wiltshire pre-dates the mid-Eocene (Summerfield & Goudie Reference Summerfield, Goudie and Jones1980; Green Reference Green1997a; Reference Green1997b), Paleogene sediments of mid-Eocene age or earlier would need to have once extended across the site of the east-central Salisbury Plain.

2. b) These sediments would need to include sandy horizons that were, at least locally, of sufficient thickness to be silicified into 1–2 m thick sarsens (analogous groundwater silcrete lenses in the Paris Basin formed in deposits up to 10 m thick; Thiry et al. Reference Thiry, Ayrault and Grisoni1988).

3. c) The sandy horizons would need to be relatively ‘clean’, ie, devoid of clay minerals that would otherwise inhibit the development of the quartz overgrowth cements typical of saccharoidal sarsens (Smale Reference Smale1973; Dewers & Ortoleva, Reference Dewers and Ortoleva1991; Ullyott et al. Reference Ullyott, Nash and Huggett2015).

4. d) The sands would also need to be situated in a geological structural context (eg, a synform) that would promote the sustained flow of silica-bearing groundwater required to cement 1–2 m thick groundwater silcrete lenses (Thiry et al. Reference Thiry, Ayrault and Grisoni1988; Nash & Ullyott Reference Nash, Ullyott, Nash and McLaren2007).

5. e) Most importantly, to exhibit the same geochemistry, the sands would need to comprise a similar mix and relative abundance of non-quartz minerals as those that were cemented to form the sarsens at West Woods.

Factor a) is perfectly feasible. Establishing the former distribution of Paleogene sediments in Wiltshire is not easy; the Paleogene outcrop is sparse (Fig. 6), and the palaeogeography of the time is poorly constrained (King Reference King, Brenchley and Rawson2006). However, from the available geological evidence, it is highly probable that sediments of latest Palaeocene to Early–Mid-Eocene age once extended across Salisbury Plain (Curry Reference Curry1965; King Reference King, Brenchley and Rawson2006; Reference King2016). The Late Palaeocene Upnor Formation (basal Lambeth Group), if present, would have been very thin in the Wiltshire area (Booth et al. Reference Booth, Hopson, Farrant, Newell, Marks, Bateson, Woods, Wilkinson and Evans2011; Aldiss Reference Aldiss2014). However, outliers of the Late Palaeocene–Early Eocene Reading Formation (Lambeth Group) and Early Eocene London Clay Formation (Thames Group) outcrop in the Savernake Forest to the south-east of Marlborough. Reading Formation deposits also occur as an isolated outlier capping Sidbury Hill, north-west of Tidworth. Thicker (up to 20 m) sequences of Reading Formation, London Clay, and Early–Mid-Eocene Wittering Formation (Bracklesham Group) are present to the south-east of Salisbury (Hopson et al. Reference Hopson, Farrant, Newell, Marks, Booth, Bateson, Woods, Wilkinson, Brayson and Evans2007).

Fig. 6. Simplified geological map of the area between the Marlborough Downs and Salisbury. Geological structures, after Mortimore et al. (Reference Mortimore, Gallagher, Gelder, Moore, Brooks and Farrant2017).

The distribution of Clay-with-flints, a residual deposit created by the weathering of the Paleogene cover and solution of the underlying Chalk (Hopson et al. Reference Hopson, Farrant, Newell, Marks, Booth, Bateson, Woods, Wilkinson, Brayson and Evans2007), suggests that Paleogene sediments – most likely the Reading Formation – may have outcropped even further west (Bateman Reference Bateman1988). Areas of Clay-with-flints occur around Marlborough and to the east and west of Salisbury (Fig. 6). Clay-with-flints is only mapped by the British Geological Survey on Salisbury Plain to the west of Shrewton, and in isolated patches to the east of the River Avon near Upavon. It has, however, been identified north of Durrington and more widely in solution hollows in the Chalk within the study area (Booth et al. Reference Booth, Hopson, Farrant, Newell, Marks, Bateson, Woods, Wilkinson and Evans2011).

Factors b) and c) are less likely. Whilst Paleogene sediments were almost certainly present over the east-central Salisbury Plain, it is doubtful that they were sufficiently thick or ‘clean’ to permit the development of thick saccharoidal sarsen lenses. The Upnor Formation comprises gravel beds and fine to coarse grained glauconitic sands with variable clay and silt content (Booth et al. Reference Booth, Hopson, Farrant, Newell, Marks, Bateson, Woods, Wilkinson and Evans2011; Aldiss Reference Aldiss2014). The Reading Formation, London Clay, and Wittering Formation in the area are dominated by clays, silts, thin sand units, and sandy ironstones deposited in floodplain, deltaic, estuarine, marginal-marine, and inner neritic environments (White Reference White1925; King 2006; Reference King2016; Hopson et al. Reference Hopson, Farrant, Newell, Marks, Booth, Bateson, Woods, Wilkinson, Brayson and Evans2007; Aldiss et al. Reference Aldiss, Newell, Marks, Hopson, Farrant, Royse, Aspden, Evans, Smith, Woods and Wilkinson2010; Booth et al. Reference Booth, Hopson, Farrant, Newell, Marks, Bateson, Woods, Wilkinson and Evans2011; Entwhistle et al. Reference Entwhistle, Hobbs, Northmore, Skipper, Raines, Self, Ellison and Jones2013; Barnet Reference Barnet2023). Sandy units are present within the Reading Formation around Newbury and in the north Hampshire Basin but are at their thickest further east in the London Basin (Entwhistle et al. Reference Entwhistle, Hobbs, Northmore, Skipper, Raines, Self, Ellison and Jones2013; King Reference King2016). The only thick, well-sorted, sandy units occur in the Reading Formation south-east of Salisbury, where they are interpreted as representing a fluvial channel within otherwise clay rich floodplain deposits (Hopson et al. Reference Hopson, Farrant, Newell, Marks, Booth, Bateson, Woods, Wilkinson, Brayson and Evans2007; Booth et al. Reference Booth, Farrant, Hopson, Woods, Evans and Wilkinson2008). Sarsen formation in the Salisbury Plain area would require a similarly large sandy unit within the Reading Formation (Aldiss Reference Aldiss2014), but any evidence of this has long been eroded.

Factor d) is doubtful. Even if deposits of thick sandy Paleogene sediments were present over the east-central Salisbury Plain, it is unlikely that they were in a structural context that would promote extensive groundwater silicification. The region between the Marlborough Downs and Salisbury is characterised by belts of broadly east–west trending folds and faults in the north and south, with wider less deformed areas in between (Mortimore et al. Reference Mortimore, Gallagher, Gelder, Moore, Brooks and Farrant2017; Allen & Crane Reference Allen and Crane2019). The Paleogene sediments around Marlborough are situated within a synformal structure, part of a belt of folds stretching from Pewsey to Basingstoke (marked as the Pewsey Structure on Fig. 6). This includes the Pewsey anticline, initiated during Early Alpine mountain-building phases in the Late Cretaceous prior to the main phase of Alpine folding during the Neogene (Varney Reference Varney1921; Booth et al. Reference Booth, Hopson, Farrant, Newell, Marks, Bateson, Woods, Wilkinson and Evans2011). Equivalent sediments south-east of Salisbury are preserved in the Alderbury–Mottisfont Syncline (immediately north of the Dean Hill Anticline on Fig. 6), the easterly end of the east–west trending Mere–Wardour–Portsdown fold and fault zone. The Chalk underlying the intervening area of Salisbury Plain exhibits only a very gentle dip to the south. While fold structures probably exist in this area (speculative folds are identified by Mortimore et al. Reference Mortimore, Gallagher, Gelder, Moore, Brooks and Farrant2017 south of Stonehenge), any synforms are unlikely to be at the scale and amplitude of those mapped to the north and south.

Factor e) is also unlikely. The geochemical composition of the sands that became cemented to form sarsen stone would depend on (i) the mineralogy of the sediments eroded from the landmass that existed to the north-west of the study area during the Paleogene (King Reference King, Brenchley and Rawson2006) and (ii) the sorting of these sediments during transport in fluvial, estuarine, or shallow-marine regimes. Evolution of the fluvial and near-coastal system is likely to have driven variation of the deposited sand, both laterally and vertically through time. The result of this interplay of processes can be seen in the Marlborough Downs, where Nash et al. (Reference Nash, Ciborowski, Ullyot, Parker Pearson, Darvill, Maniatis, Greaney and Whitaker2020) have shown that the geochemical signature of sarsens varies over short (sub-km scale) distances. A comparison of the signature of boulders within the sarsen train at Lockeridge Dene with that at West Woods provides a useful illustration. The Lockeridge sarsens, which originated on the plateau surface 1–2 km west of West Woods, consistently record lower Zr-normalised trace element ratios than those at West Woods for all 21 immobile trace elements used by Nash et al. (Reference Nash, Ciborowski, Ullyot, Parker Pearson, Darvill, Maniatis, Greaney and Whitaker2020) to discriminate between source areas. These differences are likely driven by the sands within the Lockeridge sarsens having a greater abundance of zircon and potentially different abundances of Rare Earth Element-bearing minerals. Boulders sampled at sites north of the River Kennet also show different abundance patterns for many elements compared to West Woods. If sarsens within a 6 km radius of West Woods exhibit such variable trace element profiles, it seems unlikely that sarsens even further away (up to 23 km to the south) would have an identical geochemistry to West Woods, driven by a near-identical set of hydrodynamic conditions at the time of deposition.

In summary, it is hard to find a geological explanation for why the geochemistry of the Cuckoo Stone, Tor Stone, and Stone 58 at Stonehenge should be so similar (Fig. 5) unless they came from a common source area – West Woods. The preceding arguments do not preclude the formation of sarsen boulders in the area now occupied by Salisbury Plain. They do, however, suggest that any natural sarsens would be unlikely to exhibit the same immobile trace element profile as the boulders at West Woods. Sarsens would also be unlikely to occur in the same numbers and reach the same size as those found to the north. This latter conclusion is supported by the distribution and size of sarsens on Salisbury Plain today. Sarsens were mapped to the south of the Vale of Pewsey during the Sarsen Stones of Wessex project (Bowen & Smith Reference Bowen and Smith1977; Whitaker Reference Whitaker2020). However, as Green (Reference Green1997a, 6–7) notes, lone sarsens were recorded in their supposed natural context at only 28 sites. Of these, the largest was less than 3 m in length and the majority very much smaller. At 11 other sites, groups of two or three sarsens were recorded or more numerous cobbles of sarsen noted in river gravels. Sarsen was present in only 18 prehistoric structures (as small pieces or larger blocks) and 17 historic buildings (almost always as one or two small stones) across the entire mapped area. Green used this evidence to argue that there was no sign of a locality to the south of the Vale of Pewsey that could have yielded the large sarsen blocks used at Stonehenge. Unless almost all the sarsens in the east-central Salisbury Plain were monumentalised, and virtually no smaller boulders left behind, the same is likely true for the smaller Cuckoo and Tor stones.

Archaeological implications

Our inference that the Cuckoo and Tor stones were introduced to the Stonehenge landscape from the Marlborough Downs prompts a re-assessment of the excavated archaeological context from which the stones are thought to have originated. During excavation work, Richards (Reference Richards and Parker2020) reported two shallow solution features in the surface of the Chalk, adjacent to the two stones, and considered that the features probably marked the original hollows from which each stone had been extracted. In support of this interpretation, Richards noted that similar features have been recorded beneath sarsen boulders, where the decalcification of the Chalk was apparently accelerated by rainwater run-off around the stone (see Bowen & Smith Reference Bowen and Smith1977, 193). However, Bowen and Smith also described an instance where the Chalk surface beneath a sarsen was totally unaltered; this implies that the occurrence of a solution feature may not necessarily be causally related to the presence of a stone. Hollows of this type have been recorded in quantity where large areas of Chalk have been exposed in archaeological excavations and where sarsens are absent (eg, Wessex Archaeology 2019, 12). Solution can also result from a diverse range of decalcification mechanisms, including those related to periglacial activity or tree boles or throws (Evans et al. Reference Evans, Pollard and Knight1999). Such solution features may contain undisturbed archaeological material in a relict sorted horizon that is preserved on the surface of the hollow, including refitting artefacts (Richards Reference Richards1990, 163). This eventuality may account for the preservation of deposits interpreted as a low cairn in the base of the hollow adjacent to the Tor Stone (see above).

Our results also prompt a reconsideration of the timing of sarsen use in the Stonehenge landscape. No datable material has been collected from the excavated stone-holes of either the Cuckoo Stone or Tor Stone. However, radiocarbon determinations derived from closely linked pits at the Cuckoo Stone, in combination with the shared characteristics of flint technology associated with both stones, indicate that they may also have been installed early in the 3rd millennium bce; this is broadly contemporary with the Phase 1 monument at Stonehenge. That both sarsens existed in their present locations at some point in the Neolithic period may be supported by the fact that they apparently attracted subsequent Bronze Age and Romano-British activity (Richards Reference Richards and Parker2020, 366, 397). Parker Pearson et al. (Reference Parker Pearson, Pollard, Richards, Thomas, Tilley and Welham2022) compiled a corpus of contemporaneous monuments (including Late Neolithic pits at Woodlands, Ratfyn, and Bulford) that were linked by pottery of the Woodlands sub-style of Grooved Ware, in a group that also included the West Amesbury henge. The Woodlands type site itself remains undated. However, additional pits containing Woodlands sub-style Grooved Ware pottery have been identified within a radius of approximately 12 km of Stonehenge at Harnham Park (south-west of Salisbury), Porton Down, and Upavon Down. These pits have consistently returned dates from early in the 3rd millennium bce, confirming the age of the sub-style (Brook Reference Brook, Copper, Whittle and Sheridan2024) with probable chronological links to the two stones. Parker Pearson et al. (Reference Parker Pearson, Pollard, Richards, Thomas, Tilley and Welham2022) included the Cuckoo Stone and Tor Stone in their corpus, which indicated the use of sarsen by this date, on the basis that the stones were thought to be indigenous to the area. The suggestion that the two stones were instead introduced requires a significant amendment to the use of sarsen in the area.

These examples are not alone in the Stonehenge landscape. Stukeley (Reference Stukeley1740) described five individual blocks, including one ‘about 3 miles [c. 5 km] off northward, in Durrington Fields’ (1740, 56) and probably the Cuckoo Stone that he speculated may have originated from a dismantled temple related to the source of the Stonehenge Avenue. Most were dispersed along the River Avon valley and are currently unlocated with no chronological or archaeological context. Richards (Reference Richards and Parker2020, 362) similarly documented an isolated stone, possibly a boundary marker, in a discussion to support an argument for indigenous sarsens in the area. Sarsen fragments have been recovered from other parts of the locality including an extensive scatter found in ploughsoil on the King Barrow Ridge (Richards Reference Richards1990). This assemblage may have been derived from the breaking of multiple stones or a small number of monoliths; however, the area has produced dated material spanning all phases of the Neolithic period (Harding Reference Harding1988; Richards Reference Richards1990; Cleal et al. Reference Cleal, Walker and Montague1995; Roberts et al. Reference Roberts, Barclay, Bishop, Bronk-Ramsey, Campbell and Canti2020) making the inclusion of this material in any discussion covering the arrival of sarsen on the Stonehenge landscape inadmissible.

Our inference from analysis of the composition and context of Cuckoo Stone and the Tor Stone, that sarsen was moved into the Stonehenge landscape as early as the early 3rd millennium bce should not be surprising. Movement of stone across the landscape is known from the Early Neolithic period. For example, blocks of Oolitic Limestone were incorporated into the façade of the West Kennet long barrow (Piggott Reference Piggott1962). Sarsen may also have been moved in smaller quantities, as suggested by a large flake of saccharoidal sarsen (used as a hammer) from an Early Neolithic pit at Barrow Clump, Netheravon, in the River Avon valley, a location where the material is apparently uncommon (Andrews et al. Reference Andrews, Last, Osgood and Stoodley2019). The practice of using sarsen boulders as monoliths may have been initiated alongside the arrival of Grooved Ware pottery from Orkney, where stone was introduced to construct monuments such as the Stones of Stenness, by the early 3rd millennium bce (Ritchie et al. Reference Ritchie, Marwick, Henshall, Savory, Clutton-Brock and Caseldine1978; Garrow & Wilkin Reference Garrow and Wilkin2022). This spread of ideas may have extended beyond the introduction of a pottery style to include other practices, such as the use of exotic stone objects, eg, a macehead of banded gneiss (a rock type that outcrops in north-west Scotland, including the Outer Hebrides) that was found at Stonehenge (Cleal et al. Reference Cleal, Walker and Montague1995, 394).

The apparent introduction of sarsen boulders to the Stonehenge landscape during the early 3rd millennium bce re-opens the possibility that sarsens, which are largely undressed, may have been included in Phase 1 of the development of the monument, some 400–500 years earlier than the principal phase of sarsen construction. The Heelstone and two extant Station Stones, identified by Nash et al. (Reference Nash, Ciborowski, Ullyot, Parker Pearson, Darvill, Maniatis, Greaney and Whitaker2020) as likely to have originated from West Woods, remain the most obvious candidates (Cleal et al. Reference Cleal, Walker and Montague1995, 289; Parker Pearson et al. Reference Parker Pearson, Pollard, Richards, Thomas, Tilley and Welham2022, 89) but are otherwise undated. The surviving Station Stones are of comparable size and estimated weight to the Cuckoo and Tor stones. However, given the proposed date at which the Cuckoo Stone and Tor Stone were introduced, they are unlikely to represent the two missing Station Stones from Stonehenge. Furthermore, Richards (Reference Richards and Parker2020, 404) speculated that sarsen flakes that were recovered from the cairn adjacent to the Tor Stone may have been related to stone dressing at Stonehenge. The origin of these flakes also remains unresolved; however, our revised chronology places the Tor Stone contemporary with Phase 1 at Stonehenge, a phase for which there is no evidence for stone dressing at the monument, thereby suggesting that Stonehenge was not the source. Our results supplement arguments for the early introduction of sarsen stones to Stonehenge but do nothing to confirm or deny the date of arrival of the bluestones at the monument or at the West Amesbury henge, an aspect that has been debated extensively (see Parker Pearson et al. Reference Parker Pearson, Pollard, Richards, Thomas, Tilley and Welham2020; Reference Parker Pearson, Pollard, Richards, Thomas, Tilley and Welham2022).

Our results may also have spiritual or symbolic implications. West Woods has now been suggested as the likely primary source for the sarsens used in the construction of Stonehenge and – in this study – two other Neolithic monuments in the Stonehenge landscape. This is despite the fact that large sarsen boulders were available in other parts of the Marlborough Downs. Nash et al. (Reference Nash, Ciborowski, Ullyot, Parker Pearson, Darvill, Maniatis, Greaney and Whitaker2020) noted that the West Woods area contained traces of established early prehistoric occupation from the Mesolithic period onwards, which may have influenced the choice for exploitation. West Woods also lies approximately 5 km to the east of Milk Hill which, at 295 m aOD, forms the highest point in the locality and a potential spiritual link to the heavens for the area. This reverence may have created an embedded memory that was recalled during Phase 2 of the development of Stonehenge, some 400–500 years after initial exploitation of the site.

The introduction of sarsen stones into the Stonehenge landscape required significant motivation and effort. In the context of the Cuckoo and Tor stones – the only recorded monoliths on the east side of the King Barrow Ridge – the process must have incorporated both detailed planning and forethought to determine the role and ultimate position of each stone. Parker Pearson and Ramilisonina (Reference Parker Pearson1998a; Reference Parker Pearson1998b) included the sites of the two stones within a symbolic Land of the Living, where the monuments at Woodhenge and Durrington Walls were constructed of wood. They contrasted this landscape with a Land of the Dead, west of the King Barrow Ridge, which was epitomised by the use of stone at Stonehenge.

The insertion of stone monoliths into a world of the living, where human remains were found in the centre of the timber ring, forming an integral part of Woodhenge (Cunnington Reference Cunnington1929; Ruggles & Chadburn Reference Ruggles and Chadburn2024), may seem somewhat anomalous. However, excavations at Woodhenge have indicated that a stone ‘cove’ (Parker Pearson et al. Reference Parker Pearson, Pollard, Richards, Thomas, Tilley and Welham2022, 107) may have formed an integral part of that monument when the timber structure was enclosed by a ditch c. 2450 bce (Ruggles & Chadburn Reference Ruggles and Chadburn2024). The landscape context can, however, be considered in more detail using visibility analysis (Fig. 7). Separate visibility analyses were undertaken to define areas that are visible from the locations of the Cuckoo Stone and Tor Stone (Figs 8 & 9). A value of 1.65 m, representing the average height of a human (Gillings & Wheatley Reference Gillings, Wheatley, Gillings, Haciguzeller and Lock2020), was used as the observer offset at each location and added to the ground elevation value. This provided a DTM height for the Cuckoo Stone and Tor Stone of 108.93 m and 109.51 m aOD respectively. Additional visibility analyses (total viewsheds) were undertaken to identify areas in the landscape from which each stone was visible (Figs 10 & 11). A height of 1.65 m was included, but this time as a complete surface offset (ie, 1.65 m was added to the entire DTM). The approximate thickness of the Cuckoo Stone and Tor Stone (1 m) was added to the observer offset, with 1 m being the minimum default offset in the visibility tool. The visibility analyses are presented overlying a Multi-directional Hillshade (illumination angles R = 315°, G = 15°, B = 75°), derived from the 1 m DTM and generated using the Relief Visualisation Toolbox (RTV) version 2.2.1 (Kokali et al. Reference Kokali, Zakšek and Pehani2013).

Fig. 7. Landscape profile showing the respective locations of the two stones related to the River Avon valley. Heights are derived from the 1 m DTM.

Fig. 8. Visibility analysis showing areas visible from the Cuckoo Stone, clipped to 3440 m (see text) overlying a Multi-directional hill shade (Illumination angles R = 315°, G = 15°, B = 75°) derived from 1 m DTM.

Fig. 9. Visibility analysis showing areas visible from the Tor Stone, clipped to 3440 m (see text) overlying a Multi-directional hill shade (Illumination angles R = 315°, G = 15°, B = 75°) derived from 1 m DTM.

Fig. 10. Visibility analysis (total viewshed) showing areas from which the Cuckoo Stone is visible, overlying a Multi-directional hill shade (Illumination angles R = 315°, G = 15°, B = 75°) derived from 1 m DTM.

The results of visibility analysis suggest elements of planning for the two stones, linking them not only spatially with the sites at Woodlands and Bulford, but more clearly with one another on opposite sides of the River Avon. The intervisibility of the two stones is likely to have been an essential feature of their locations, near the boundaries of their respective overlapping viewsheds, as the DTM indicates. The Cuckoo Stone, located below the crest of the King Barrow Ridge, dominates the viewshed to the south-east while the Tor Stone, which lies below the corresponding eastern skyline, overlooks land to the north-west. Further, the DTM indicates that a transect drawn between the two stones (Fig. 7) passes close to the apex of a meander in the River Avon at a point where it is approximately equidistant from each stone and potentially intervisible, both from and towards both stones. This low spur in the river, together with the surrounding downland, is likely to have been predominantly open with variable patches of deciduous woodland with hazel during the Mesolithic and Early Neolithic periods, which may have obscured visibility (French et al. Reference French, Scaife, Allen, Parker Pearson, Pollard, Richards and Welham2012; Reference French, Carey, Allen, Toms, Wood, de Smedt, Crabb, Scaife, Gillings and Pollard2024). These authors have stressed the attraction of open landscapes to locate monuments for prehistoric communities. This part of the River Avon valley underwent significant environmental transformation at approximately 2900 bce (French et al. Reference French, Scaife, Allen, Parker Pearson, Pollard, Richards and Welham2012, 30), contemporary with the suggested erection of the sarsens. This episode included dramatic tree and shrub clearance across the downlands, with sedges and alder near the river, which collectively may have improved visibility of the river from the surrounding highland – a view that is currently denied (see Fig. 2B, above).

Fig. 11. Visibility analysis (total viewshed) showing areas from which the Tor Stone is visible, overlying a Multi-directional hill shade (Illumination angles R = 315°, G = 15°, B = 75°) derived from 1 m DTM.

Richards (Reference Richards2005) remarked on the frequency with which standing stones on Orkney were often paired or grouped. He emphasised how a large standing stone on the banks of the Loch of Stenness, known as the Watchstone, was formerly paired with another stone, known only from a stone hole, and provided a possible ‘pathway’ (Richards Reference Richards2005, 216) from the loch to the Stones of Stenness. This role in the landscape could also be repeated in domestic structures, where standing stones created openings at doorways in Orcadian houses. Our model makes it possible to view the Cuckoo Stone and Tor Stone not only as integral elements of contemporary sites at Woodlands and Bulford but also, drawing on influences from Orkney, as a portal to the Stonehenge landscape. That the two stones were positioned at almost identical elevations on opposing banks of the River Avon is unlikely to have been purely by chance. These possible origins may have set the scene for the prolonged development of the area towards the end of the Late Neolithic. This would have included the further introduction of sarsen from West Woods and other sites to remodel Stonehenge, together with the development of henges across the local landscape, including the major centres at Durrington Walls and Woodhenge.