Details

The monument falls into two areas of protection and includes a NNW-SSE aligned
linear earthwork, interpreted as a medieval earthwork constructed across a
shallow sandstone valley. The earthwork coincides with the modern Kent-Surrey
county boundary and survives for a total length of around 315m. It takes the
form of a large bank up to 15m wide and 3m high, flanked to the south west by
a ditch up to 9m wide and 1.5m deep. Towards the north west, the ditch has
become infilled during past, modern ploughing and survives as a buried
feature. The south eastern end of the earthwork is formed by a well-defined,
rounded terminal, whilst the original north western end has been destroyed by
post-medieval sand extraction. The construction of an embankment for the
modern A25 between Limpsfield and Westerham through the central part of the
monument has disturbed a short section of the earthwork, and this area is
therefore not included in the scheduling. The road construction work and
subsequent gas main laying has also partly disturbed the earthwork immediately
to the south east of the road, and the original profile of a short section of
the adjacent ditch has been altered by the digging of a small stock watering
pond.
The linear earthwork is thought to have been constructed between the fifth and
eighth centuries AD, when it is likely to have formed a strategically
important part of the boundary between rival Anglo-Saxon kingdoms. It was
designed to control the communication route which linked the two territories
and ran along the valley bottom on the line of the modern A25.
The modern fences which cross the monument are excluded from the scheduling,
although the ground beneath is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.

Source: Historic England

Reasons for Scheduling

A small number of substantial and defensible boundary features have been
identified as frontier works marking territories in the early medieval period.
Up to 50 examples are known with a fairly wide distribution across England,
including examples in southern England, East Anglia, Yorkshire, Derbyshire and
along the Welsh border.
Identified remains extend over distances from as little as 300m up to as much
as 240km in the case of Offa's Dyke. They survive in the form of earthworks
and as buried features visible as cropmarks or soilmarks on aerial
photographs. They appear often to have been constructed across the natural
grain of the landscape and, although many examples consisted of a single bank
and flanking ditch, to vary considerably in their form and dimensions, even
along different stretches of the same boundary, depending upon local
topography.
Evidence from contemporary documentary sources, excavation and survey suggests
that they were constructed in the early medieval period between the fifth and
eighth centuries AD. Some were relatively ephemeral, perhaps in use for only a
few years during periods of local strife; others, such as Offa's Dyke,
constructed between Wales and Mercia, have formed long-lived territorial
and/or military boundaries in use for several centuries.
As a rare monument type of considerable importance to the study of early
medieval territorial patterns, all surviving examples are identified as
nationally important.

Although it has suffered some subsequent disturbance, the linear earthwork
south west of Covers Farm survives well, and is represented by substantial
earthworks over most of its original extent. It can be expected to retain
important archaeological and environmental evidence relating to the
construction and original use of the monument.

Source: Historic England

Sources

Books and journals
Clark, A, 'Surrey Archaeological Collections' in A Cross Valley Dyke on the Surrey-Kent Border, , Vol. 57, (1960), 72-74

Source: Historic England