Prehistoric settlement and field system at Porth Killier, St Agnes


Heritage Category: Scheduled Monument

List Entry Number: 1014998

Date first listed: 04-Oct-1996


Ordnance survey map of Prehistoric settlement and field system at Porth Killier, St Agnes
© Crown Copyright and database right 2018. All rights reserved. Ordnance Survey Licence number 100024900.
© British Crown and SeaZone Solutions Limited 2018. All rights reserved. Licence number 102006.006.
Use of this data is subject to Terms and Conditions.

The above map is for quick reference purposes only and may not be to scale. For a copy of the full scale map, please see the attached PDF - 1014998 .pdf

The PDF will be generated from our live systems and may take a few minutes to download depending on how busy our servers are. We apologise for this delay.

This copy shows the entry on 10-Dec-2018 at 20:49:30.


The building or site itself may lie within the boundary of more than one authority.

District: Isles of Scilly (Unitary Authority)

Parish: St. Agnes

National Grid Reference: SV 88227 08503


Legacy Record - This information may be included in the List Entry Details.

Reasons for Designation

The Isles of Scilly, the westernmost of the granite masses of south west England, contain a remarkable abundance and variety of archaeological remains from over 4000 years of human activity. The remote physical setting of the islands, over 40km beyond the mainland in the approaches to the English Channel, has lent a distinctive character to those remains, producing many unusual features important for our broader understanding of the social development of early communities. Throughout the human occupation there has been a gradual submergence of the islands' land area, providing a stimulus to change in the environment and its exploitation. This process has produced evidence for responses to such change against an independent time-scale, promoting integrated studies of archaeological, environmental and linguistic aspects of the islands' settlement. The islands' archaeological remains demonstrate clearly the gradually expanding size and range of contacts of their communities. By the post- medieval period (from AD 1540), the islands occupied a nationally strategic location, resulting in an important concentration of defensive works reflecting the development of fortification methods and technology from the mid 16th to the 20th centuries. An important and unusual range of post- medieval monuments also reflects the islands' position as a formidable hazard for the nation's shipping in the western approaches. The exceptional preservation of the archaeological remains on the islands has long been recognised, producing an unusually full and detailed body of documentation, including several recent surveys. Stone hut circles are what remain of the round houses of early inhabitants on the Isles of Scilly. Excavation has shown that round houses were built on the islands from the Bronze Age to the early medieval period (c.2000 BC-AD 1066), though during the Romano-British period (AD 43-400) complex forms were developed with multiple rooms and annexes, classified separately as `courtyard houses'. Stone hut circles survive with rubble or earth and rubble walls or banks defining circular or ovoid internal areas. These are usually levelled and range from 2.5-13m across, though they are generally 3-5m across. The walls may incorporate natural ground-fast boulders or outcrops and sometimes have a facing of edge-set slabs, large blocks or occasionally of coursed rubble walling along one or both faces. Some hut circle walls show entrance gaps, 0.5-2m wide, sometimes flanked by end-set slabs or blocks. Remains of roofing are not preserved but excavations have revealed post- and stake-holes for roof supports and internal subdivisions. Excavation has also revealed a range of domestic artefacts and, in a small number of later examples, evidence for metal working. The deposits within and around hut circles may also include quantities of midden material. Stone hut circles may occur singly or in small or large groups, either closely spaced or dispersed. At least 136 hut circles are recorded on the Isles of Scilly. These are widely distributed but are more likely to be found towards the lower land, the coastal margins and the inter- tidal zone, reflecting the subsequent submergence of much low-lying land that formed the original landscape context in which many such settlements were built. Hut circles may be associated with broadly contemporary field systems and funerary monuments, while some examples dating to the Romano-British and early medieval period are included within sites forming religious foci. They embody a major part of our evidence on the economy and lifestyle of the islands' past inhabitants. Their longevity of use and their relationships both with other monument types and with the islands' rising sea level provides valuable information on the developing settlement patterns, social organisation and farming practices throughout a considerable proportion of the islands' human occupation.

This prehistoric settlement site at Porth Killier contains an unusually good survival of Bronze Age structural remains in direct association with extensive and undisturbed contemporary occupation layers. From a programme of detailed recording, sampling and analysis, this settlement is known to be a particularly rich and closely datable source of economic, environmental and artefactual information of national significance for studies of this period; its faunal assemblage also includes many species not previously recorded in Bronze Age deposits on Scilly and it forms one of the main sites quoted in palaeo-environmental assessments of the Isles of Scilly. Despite encroachment of the coastal cliff, archaeological prospecting has indicated the considerable area behind the cliff face in which these buried stratified deposits will survive and has thereby confirmed the long term presence of important prehistoric settlement remains at this location. The prehistoric field system in this monument shows clearly the manner of prehistoric land division employed, and its proximity to similar remains beyond the monument near Higher Town demonstrate the broader context in which the settlement focus developed. The lynchetting associated with parts of the field system will also preserve important information on the development of prehistoric land use, complementing the data from the settlement.


Legacy Record - This information may be included in the List Entry Details.


The monument includes a prehistoric hut circle settlement on the south east of Porth Killier on northern St Agnes in the Isles of Scilly. Extending east from the settlement, behind Kallimay Point, the monument also includes a broadly contemporary prehistoric field system. The prehistoric settlement contains at least three stone hut circles, spaced 1m-2m apart and exposed in an ENE-WSW row along the low coastal cliff face of south eastern Porth Killier. The hut circles have rounded internal areas, up to 5m across at their line of truncation by the cliff face and defined by inner facing walls of granite slabs, largely coursed but incorporating some edge-set slabs, surviving up to four courses and 0.9m high. The facing in the central hut circle includes a reused hollowed slab from an early type of millstone called a saddle quern. The facing walls are backed by layered soil deposits and middens of occupation debris. Detailed recording of the central hut circle revealed a floor partly built up of redeposited subsoil and crossed by a slab-lined and covered drain. Over the floor lay a deep midden deposit containing a rich assemblage of occupation debris including sherds of Bronze Age pottery, broken and burnt saddle quern rubber-stones, charcoal, fragments of limpet shells, fish, bird and sheep or goat bones and charred cereal grains. The cliff section also reveals that the hut circles are accompanied by deposits, generally totalling 1m thick, comprising dumped material contemporary with the settlement and later gradual accumulations. Such deposits have been recorded at various times over at least 50m of the cliff face, their south western limit being unknown due to masking by early coastal defence works. Towards their north east end these deposits include rubble spreads considered to denote former locations of further hut circle sites; a saddle quern is known to have eroded from one of these sites onto the upper shore. In the immediate vicinity of the hut circle settlement, at least eight further middens have been recorded among the adjacent dumped deposits. Most comprise small accumulations of limpet shells and bone but the largest extends over 4.5m long and 0.6m deep beside the facing wall of the north east hut circle. These middens have also produced Bronze Age pottery sherds, both decorated and plain, and environmental analysis of the midden deposits has revealed bones of ox, sheep/goat, deer, pig, whale and grey seal, a range of bird and fish species and the visually dominant limpets. Charred and mineralised plant remains include wheat and barley, celtic bean and various weeds typical of arable land. Radiocarbon dating of charred grain from the largest midden gave a overall date range of 1680-1310 BC, in the Middle Bronze Age, while charcoal from middens to the north east of the hut circles gave a Late Bronze Age range of 1375-995 BC. Plant remains from the middens also included indicators of the wider environmental context contemporary with the settlement. Behind the cliff face, the inland extent of stratified settlement remains has been gauged by archaeological prospecting techniques, indicating that the settlement occupies a large bedrock depression, with sufficient depth of soil consistent with surviving stratified deposits mapped up to 20m behind the cliff edge of the settlement. Besides the Bronze Age settlement remains, prehistoric flint artefacts indicating earlier settlement have been found eroding from an early soil layer exposed along much of the south east cliff of Porth Killier up to Kallimay Point. Finds later than the Bronze Age settlement have also been recovered from the Porth's eroding cliff, notably sherds of Iron Age pottery, a Roman copper-alloy brooch and an early medieval sherd. Few such later period finds were found during recording of the Bronze Age settlement, suggesting a different focus for the later settlement activity. The prehistoric field system extends east from the area of the Bronze Age settlement exposed in the cliff face. On the broad spur behind Kallimay Point, and where not masked by soil deposits and vegetation, its walling is visible as lines of variously spaced or contiguous boulders, generally 1.5m wide and 0.5m high. Three walls subdivide the broad spur on a NNW-SSE axis; the central wall extends along part of the spine of the spur from a small granite outcrop on its southern summit; the north east wall follows the contour close to the present coast, turning to and truncated by the coastal cliff at the north. The third wall, on the spur's western slope, is of different character, surviving as a pronounced bank, called a lynchet, generally 2m wide and up to 1.5m high, reflecting movement of soil against the boundary due to the effects of early cultivation on the slope. At the north its straight course changes to form a wide curve, truncated on the west by the coastal cliff. A hollow along the east side of its straight sector is considered to derive from a early trackway. South west of the lynchet, a fourth boulder wall extends 50m north east-south west, curving inland at each end where it is truncated by modern pasture clearance. Further traces of the field system are also apparent in the unusually sinuous courses of some present field boundaries in the modern enclosed land immediately south of those on the spur; these sinuous lengths contrast markedly with the straight-line boundaries laid out in recent centuries and denote the earlier boundary continuing beneath and influencing the course of the modern boundary. These preserved lengths include a wall rising north west-south east to a slight hillock behind the coastally-exposed settlement focus. There it meets another sinuous wall running north east to end on one of two roughly parallel boundaries extending north west-south east along the slope behind Porth Conger; beyond this scheduling, their alignment is continued in another surviving area of early field system north of Higher Town. Beyond this monument, further prehistoric field system and settlement sites survive from 50m to the south east on the land north of Higher Town. These are the subject of a separate scheduling. All modern sea defence structures are excluded from the scheduling but the ground beneath them is included.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


The contents of this record have been generated from a legacy data system.

Legacy System number: 15450

Legacy System: RSM


Books and journals
Ashbee, P, Ancient Scilly, (1974)
Ratcliffe, J, Fieldwork in Scilly July 1993, (1994)
Ratcliffe, J, Fieldwork in Scilly 1991 and 1992, (1993)
Ratcliffe, J, Sharpe, A CAU, Fieldwork in Scilly Autumn 1990, (1991)
Ratcliffe, J, Parkes, C, Fieldwork in Scilly: March 1989, (1989)
Ratcliffe, J, Fieldwork in Scilly 1991 and 1992, (1993)
Ratcliffe, J, Lighting up the Past in Scilly, (1991)
Russell, V, Isles of Scilly Survey, (1980)
Gray, A, 'Cornish Archaeology' in Prehistoric Habitation Sites on the Isles of Scilly, , Vol. 11, (1972), 19-49
Ratcliffe, J & Parkes, C/CAU, Fieldwork in Scilly: September 1989, (1990)
Ratcliffe, J & Straker, V, Land Use and Environmental Change in the Isles of Scilly, 1995, Unpubl draft, July 1995, pp 58-62
Ratcliffe, J & Straker, V, Land Use and Environmental Change in the Isles of Scilly, 1995, Unpubl draft, July 1995, pp 58-62
Title: 1:2500 Ordnance Survey Map; SV 8808 Source Date: 1980 Author: Publisher: Surveyor:
Waters, A & Ratcliffe, J/CAU, AM 107 for Scilly SMR entry PRN 7028, (1988)
Waters, A & Ratcliffe, J/CAU, AM 107 for Scilly SMR entry PRN 7029, (1988)
Waters, A & Ratcliffe, J/CAU, AM 107 for Scilly SMR entry PRN 7033, (1988)
Waters, A & Ratcliffe, J/CAU, AM 107 for Scilly SMR entry PRN 7034, (1988)
Waters, A & Ratcliffe, J/CAU, AM 107s for Scilly SMR entries PRN 7028 & 7033, (1988)

End of official listing