Prehistoric field system on the northern slope of Mount Todden, St Mary's


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:


Ordnance survey map of Prehistoric field system on the northern slope of Mount Todden, St Mary's
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The building or site itself may lie within the boundary of more than one authority.

Isles of Scilly (Unitary Authority)
St. Mary's
National Grid Reference:
SV 92914 11602

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. Regular field systems are one of several methods of field layout known to have been employed in the Isles of Scilly from the Bronze Age to the Roman period (c.2000 BC - AD 400); closer dating within that period may be provided by the visible relationships of the field boundaries to other classes of monument with a shorter known time-span of use, or by their relationship with an earlier recorded sea level. They comprise a collection of field plots defined by boundaries laid out in a consistent manner, along two dominant axes at approximate right angles to each other. This results in rectilinear fields which may vary in their size and length:width ratio both within and between individual field systems. The fields are bounded by rubble walls or banks, often incorporating edge- or end- set slabs called orthostats. Within its total area, a regular field system may be subdivided into blocks differing in the orientations of their dominant axes. Regular field systems may be associated with broadly contemporary settlement sites such as stone hut circles. Some regular field systems on the Isles of Scilly contain a distinctive association, rarely encountered elsewhere, whereby certain of their field boundaries directly incorporate or link cairns, entrance graves and cists in some groups of prehistoric funerary monuments. Although no precise figure is available, regular field systems form one of the three principal forms of prehistoric field system, along with irregular field systems and some groups of prehistoric linear boundaries, which survive in over 70 areas of the Isles of Scilly. They provide significant insights into the physical and social organisation of past landscapes and they provide evidence for the wider contemporary context within which other nationally important monuments were constructed.

The prehistoric field system on the northern slope of Mount Todden survives well, clearly displaying the manner in which it was laid out and with only minor and limited disturbance from a water pipe trench. The field system retains substantial lynchets which the recent observations have confirmed will preserve earlier land surfaces and evidence for cultivation methods and boundary structures contemporary with the lynchets' formation. The nearby broadly contemporary settlement and funerary remains on Mount Todden and Toll's Island provide the wider prehistoric context for this field system, giving valuable evidence for the organisation of land use in the pre-submergence landscape of the islands.


The monument includes a prehistoric field system on Mount Todden, a prominent rounded spur on the east coast of St Mary's in the Isles of Scilly. The field system survives over approximately 0.5ha of the spur's northern slope as a series of small adjoining plots defined by a network of slight banks, mostly 0.1m-0.75m high but over 3m high on the lower slope in the north east corner of the scheduling. The banks generally run WNW-ESE or north east- south west, almost directly along or across the slope, giving a pattern of small rectangular plots. Where banks follow the contour they appear on the slope as marked steps called lynchets, reflecting soil movement against and from the former boundaries due to prehistoric cultivation on the steep slope. Observations in 1992 during pipe trenching across the lynchet in the north east of the scheduling revealed a stone bank or wall facing the upper part of the lynchet, while the lynchet's stony soil sealed an earlier old soil layer. The prehistoric field system survives largely within a modern pasture field though some banks extend into unenclosed land to the east. At least seven field plots are visible, the largest approximately 0.1ha in extent in the north west and north of the modern field. On the higher land in the south of the scheduling, three smaller plots are stepped one behind the other up the slope; the north west banks of the lower two of these plots extend in parallel up the slope, 1.5m apart, appearing as a narrow trackway. Late 19th century maps show that two of these banks formed the 19th century course of the present field's south east wall, since realigned 10m to the south east. However the continuation of at least one of those banks beyond the 19th century wall courses and their conformity with neighbouring prehistoric lynchets indicates their prehistoric origin. The lynchet sectioned by the pipe trench in 1992 is also extended by the line of a modern field wall to the WNW. Samples taken during the pipe trenching revealed good pollen preservation in the lynchet's soil fabric; two stone artefacts were found beneath the turf on top of the lynchet: a probable rubber-stone from a prehistoric saddle quern, a type of hand-mill for grinding corn, and a broken whetstone. This is one of a series of prehistoric field systems surviving on the coastal spurs and downs of St Mary's. That on Mount Todden is inter-visible with a broadly contemporary field system on Toll's Island, 350m to the north east across the present Pelistry Bay but formerly linked by dry land in the pre-submergence landscape when these field systems were laid out and used. Other nearby prehistoric features include a linear boundary descending the steep eastern slope of Mount Todden, 100m to the ESE, and a large prehistoric funerary cairn located 100m SSW of this scheduling. The modern water pipe and its pipe trench are excluded from this 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:
Legacy System:


Draft plan for MPP sched proposal, Hooley, A D, Part-measured plan of Mount Todden north slope field system, (1994)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7234, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7236, (1988)
Parkes, C/CAU, AM 107 for Scilly SMR entry PRN 7238, (1988)
Ratcliffe, J, Mount Todden Down Desalination Plant Results of Watching Brief, 1994, Unpublished report for IoS Council
Title: 1:2500 Ordnance Survey Map; SV 9211 Source Date: 1980 Author: Publisher: Surveyor:
Title: 25": 1 mile Ordnance Survey Map; Cornwall sheet LXXXVII Source Date: 1908 Author: Publisher: Surveyor:


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

End of official listing

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