Causewayed enclosure, 900m west of Chimney Farm

Reasons for Designation

Between 50 and 70 causewayed enclosures are recorded nationally, mainly in southern and eastern England. They were constructed over a period of some 500 years during the middle part of the Neolithic period (c.3000-2400 BC) but also continued in use into later periods. They vary considerably in size (from 2 to 70 acres) and were apparently used for a variety of functions, including settlement, defence, and ceremonial and funerary purposes. However, all comprise a roughly circular to ovoid area bounded by one or more concentric rings of banks and ditches. The ditches, from which the monument class derives its name, were formed of a series of elongated pits punctuated by unexcavated causeways. Causewayed enclosures are amongst the earliest field monuments to survive as recognisable features in the modern landscape and are one of the few known Neolithic monument types. Due to their rarity, their wide diversity of plan, and their considerable age, all causewayed enclosures are considered to be nationally important.

The causewayed enclosure 900m west of Chimney Farm survives well despite having been levelled by ploughing. The buried remains will include archaeological and environmental evidence relating to its construction, function and the landscape in which it was built. The environmental evidence will be particularly well-preserved due to the high level of waterlogging in the lower ditch deposits. In addition, the site will provide evidence of the wider Thames Valley landscape in the prehistoric period and recent aerial photographic work by the Royal Commission on the Historical Monuments of England has shown that the site forms part of a wider group of ceremonial, settlement and related sites of the period.

Details

The monument includes a causewayed enclosure 900m west of Chimney Farm. The site lies within the flood plain of the Thames, and despite modern water management features in the vicinity, the land remains prone to waterlogging, particularly during early spring. Although no longer visible at ground level, the ditches of the enclosure are clearly visible as cropmarks on aerial photographs. These show both crop height and colour variations indicating infilled features below the modern plough soil. The enclosure is slightly oval in plan, measuring approximately 150m across and is defined by at least two circuits of interrupted ditches with possible traces of a third. These ditches are between 6m and 10m wide and will survive buried below the present ground surface. Originally, the ditches would have been separated by banks constructed from the upcast spoil excavated during their construction. These have subsequently been levelled by ploughing over time, and much of the material is almost certainly now contained in the fill of the buried ditches. A number of further features visible on aerial photographs relate to later drainage work and are not included in the scheduling.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 5 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.

Legacy

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

Legacy System number:

28185

Legacy System:

RSM

Sources

Books and journals
Benson, , Miles, , Upper Thames Gravels Survey, (1974), 39

Other
PRN 5580, C.A.O., Cropmarks - Causewayed Enclosure, (1974)

End of official list entry

All text content is available under the Open Government Licence v3.0 , except where otherwise stated. Any supplied maps are © Crown Copyright [and database rights] 2026 OS AC0000815036 and may not be reproduced without permission.