St Mary's, Isles of Scilly

Around 7000 cal BC Scilly was thought to have been a single island, rising sea levels separated St Agnes, Annet and the Western Rocks from the northern islands by around 4000 cal BC. By 2500 cal BC there was tidal flooding between the islands and rapid large scale submergence by the middle Bronze Age (Murphy, 2014:40). Considering the rapid submergence of large swathes of low lying areas, the coastal zone of the Islands contains evidence of occupation, settlement and agriculture which is unique to the South West.

Whilst some Mesolithic finds have been recorded on the Islands evidence of regular occupation is not known until the Neolithic, with permanent occupation beginning in the Bronze Age. Evidence for this is widespread throughout the Isles of Scilly but perhaps the most investigated site is Halangy Down and Halangy Porth, a settlement which was subject to occupation for thousands of years and provides clear evidence of the rising sea levels and the changing environment. Today the higher village of Halangy Down can be viewed with partially extant stone hut circles and associated field systems with the lower settlement of Halangy Porth only being visible within the cliff section from the beach.

Many of the occupation and settlement sites continued in use throughout the centuries towards the middleages, stone buildings were adapted to compliment new ways of living and working with the Isles of Scilly demonstrating a unique Island culture. Burial traditions contributed to this unique culture and this is an area that CITiZAN have explored further by recording exposed Romano-British Cist burials at Porth Cressa. First noted during the construction of a housing development in the twentieth century, a type of cist burial which is unique to this archipelago. Subsequently further 'Porth Cressa type' cists have been noted at Toll's Porth and on other Islands of the Isles of Scilly.

Halangy porth

Halangy porth is a small cove bounded to the west by the Atlantic and nationally significant archaeological remains to the north, east and south. These remains are what is left of the ‘later’ settlement, relocated here c.400 BC due to the collection of dune sands on the original settlement (Ashbee et al 1996; 11). The original settlement has largely been destroyed by rising sea levels but over the past century the remains of the earlier village have been noted in the cliff. Middens, structures, pottery and a possible cross section of a chambered cairn have all been recorded in an unsystematic way. In 1976-77 a small targeted excavation was conducted on this site which provided further evidence of the earlier settlement. As part of the CITiZAN project we will be identifying whether any archaeological remains of this settlement are still in place. 

The Later village, whilst not under imminent threat, lies between 70-250m from the current coastline and therefore lies within the remit of the CITiZAN project. Halangy Down contains the archaeological remains of the following phases of land use can be identified:

  • Ancient field systems which are revetted with stone
  • Small stone domestic structures
  • Chambered cairns and cists
  • Courtyard and associated buildings
  • Oval building 

 Here CITiZAN has been working with the existing community monitoring team on the Isles of Scilly. 


Porthcressa is a cove on the south side of the Island of St Marys, Isles of Scilly. The area of interest lies on the east of the cove where evidence has been identified relating to Bronze Age settlement and funerary monuments and Roman funerary monuments. Rescue excavation has been partially carried out on the cists of the site but one of the research themes identified during the Isle of Scilly Rapid Coastal Assessment (RCZA) was the analysis and publication of the above. 

A series of hut circles dating the Bronze Age have been identified both through aerial survey and site walkovers. In 1984 a total of four huts were recorded in the cliff face; a revisit occurred in 1988 and over 13 m of continuous occupation material was identified (Cornwall CC HER 2015, 7581.03). Artefacts recovered from this site over the years such as pottery and querns suggest that this was a domestic site. 

Currently there is no evidence for Iron Age occupation at Porthcressa. During the Roman period the site is then used for burial; a single Roman cist is known from this site. First identified in 1990 and excavated in 1994 the cist contained fragmented human remains which are considered to be a crouched inhumation burial (Cornwall CC HER 2015, 7581.07).

Toll's Porth

Toll’s Porth is a small coastal promontory on the north-west side of the Island of St. Mary’s on the Isles of Scilly.  The Historic England list entry describes the site as home to a prehistoric settlement, a Romano-British cist cemetery and civil war battery.  The site is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 and is on the Heritage at Risk Register. 

Location of Toll's Porth
Location of Toll's Porth

In September 2017, the CITiZAN team ran a three day training session, the initial focus of which was to record the archaeological remains at Toll’s Porth.  The training session started in the classroom where volunteers were introduced to archaeological recording techniques, following which the team headed to Toll’s Porth to inspect the site.  The team were accompanied by Charlie Johns from the Cornwall Archaeological Unit, who was instrumental in identifying this particular area as one which merited attention.

The site is heavily eroded seaward which makes the accurate identification of features rather complicated.  Following the initial walk over of the site, elements of the three different features described in the HE listing were thought to be identified, though the exact nature and extent of the features was debated. 


Civil War Battery – Toll’s Porth

At the highest point of the site is a flat area which is thought to be the remains of the levelled platform of the battery.  Unfortunately, the area was obscured and inaccessible due to thick vegetation growth and therefore it could not be examined in any great detail.  The slope protruding from the flat upper area was heavily eroded and no distinguishing features could be recognised, therefore no detailed recording was carried out.  The feature will continue to be monitored by local volunteers in collaboration with the Cornwall Archaeological Unit. 



‘Possible’ Prehistoric Hut Circle – Toll’s Porth

Just underneath the civil war battery to the south, lies a feature which was suggested as a prehistoric hut circle.  The scheduling information for the site refers to -

at least two stone hut circles, 1.5m apart, surviving in and behind the cliff… The curve of the northern hut circle’s wall, visible as a core of earth and rubble, to 0.8 m high, faced externally by large edge-set slabs to 0.9 m long, 0.7 m wide and 0.1m thick, now bulging outwards in the cliff exposure.  The wall is exposed over 6.5, its curve giving a projected external diameter of 7m wide for the overall hut circle; the rest of its walling and interior survives buried beneath later soil and blown sand deposits behind the cliff face.  To its south, the second hut circle has walling exposed very a similar length, incorporating blocks to 1m long by 1m wide, though cliff face erosion here encroaches into the fabric of the wall’ 

Recording the possible prehistoric hut circle at Toll's Porth
Recording the possible prehistoric hut circle at Toll's Porth

Unfortunately the features as described above are no longer visible, most likely because they have been lost due to erosion or the encroachment of soil and sand.  A section of exposed boulders and smaller stones was clearly visible and this ‘feature’ was recorded in detail.  It is hoped that as the site continues to be monitored by local volunteers along with the Cornwall Archaeological Unit, further information can be gained as more elements are exposed.

The team also used photogrammetry to produce a 3D model of the feature which can be viewed here



Cist Burial – Toll’s Porth

The presence of cist burials at Toll’s Porth has long been noted and one example which lies beneath the battery at Toll’s Porth was first described in 1949 (Ashbee, 1974).  The scheduling information refers to at least two cists, with coursed slab walls capped by flat slabs.  These are known as Porthcressa type cists and are thought to date to the 1st to 4th centuries AD.  Their name is derived from another site on St Mary’s where their characteristic form was first noted.  A total of 33 examples have been recorded throughout the Isles of Scilly so far.

 In their original form they comprise an oval or sub rectangular burial chamber constructed within pits in the subsoil which are lined with upright stones and course walling and then sealed with capstones (Robinson, 2007, 107).  Their dimensions typically average around 1.25 m in length and 0.75 m in diameter, though a few larger examples have been recorded. 

A number of examples which have been excavated in the past contained grave goods such as brooches, pottery and non-local stones.  One exceptionally rich example on the island of Bryher contained a sword, shield and mirror (Johns, 2006).

One of the cists at Toll’s Porth was reported to have been lost to cliff erosion in 1996.  The remains of the second, although very heavily eroded was identified and recorded by the CITiZAN team and volunteers in September 2017.  Unfortunately, very little of the cist remains, however, its distinctive style was still recognisable and the team undertook a scale drawing and a 3D model which can be viewed here.

The remains are very precarious and are likely to be lost in the near future as heavy erosion of the area continues. 


Recording the cist burial at Toll's Porth
Recording the cist burial at Toll's Porth


Pendrathen lies to the north of Toll’s Porth on the north-west of St Mary’s.  The name Pendrathen, is derived from the Old Cornish word (circa. 1652) ‘trathen’ meaning ‘sand-bar, and at its southern end was Pendrathen (‘end of the sand-bar’) (Thomas, 1985, 45). 

Location of Pendrathen
Location of Pendrathen

The CITiZAN volunteers described an unusual 'slipway' feature situated on the beach at Pendrathen so the team headed there to investigate further.  The feature is described in the Historic Environment Record as 'a post-medieval' slipway composed of cobbles and slabs which lies at the high water mark'.  

It does not appear to have been studied in any great detail apart from a photographic survey which was carried out in October 1990 by the Cornwall Archaeology Unit.  

A detailed plan of the feature was made using offset survey techniques. Unfortunately due to time restrictions, it was not possible to record all of the detail of the feature, however the overall character of the feature was captured. 

The centre of the slipway is composed of a fill of cobbles which range in size, though all of which fall roughly into a similar size bracket.  The edges to the west and north of the feature have a border of larger, flatter slabs and on the west side one row are placed upright as hte feature continues seaward.  

Recording the 'slipway' at Pendrathen
Recording the 'slipway' at Pendrathen

The feature lies just in front of a large deliberate cut through the cliff face and extends seaward to the high water mark.  Although it is described as a slipway, it may not necessarily have functioned as such in a traditional sense.  It may instead have been associated with the kelp industry and used to facilitate easier access between the rocky beach and the cliff path to transport freshly harvested kelp from the beach to the kelp pits which are dotted along the cliff.  The precise date of the feature is unknown, though it is likely to predate Pendrathen Quay which lies approximately 200 meters to the west along the beach and which constructed sometime around 1759 (Troutbeck, 1796).

The kelp industry was one of the key industries in the Isles of Scilly between 1684 and 1835 when the last kelp burning was recorded on the islands. 

In John Troutbeck’s work , ‘A survey of the ancient and present state of the Scilly Islands’ published in 1796, he provides a fascinating account of the industry which includes the following extract (page 32) –

“The alga marina, focus, or ore-weed, is of great benefit to these islands, and grows plentifully upon the rocks, which when the tide is out are uncovered, and all the shores expose this useful plant, as food for the cattle; yet this is not the only use they make of it, for they collect, dry and burn it, ‘till it runs into a lump, or rather a kind of salt dross, which they export to Bristol and other parts, as one principal ingredient for making glass.  It is also proper for making allum and soap.  Some years they make so much kelp, or melted ore-weed, as brings into the islands from five to seven hundred pounds”. 

The CITiZAN South-West team would love to hear from anyone who knows anything further about this feature, or from anyone who has seen similar features in other areas. 



 Ashbee, P. (1974). Ancient Scilly - From the First Farmers to the Early Christians. David & Charles.

Johns, C. (2006). An Iron Age Aword and Mirror Cist Burial from Bryher, Isles of Scilly. Cornish Archaeology4142(2002–3), 1–79.

Robinson, G. (2007). The Prehistoric Island Landscape of Scilly. Oxford: BAR British Series 447.

Thomas, C. (1985). Exploration of a Drowned Landscape - Archaeology and History of the Isles of Scilly. London: Batsford.

Troutbeck, J. (1796). A Survey of Ancient and Present State of the Scilly Isles. Sherbourne: Goadby & Lepiniere.



If you would like to find out more about the features we have been recording or wish to submit your own survey on the remains then visit our interactive map:


Civil War Battery

Possible prehistoric hut circle