Details

The monument includes a cross-dyke which lies 400m east of Aldro Farm, at the
western end of Birdsall Wold and runs north from Birdsall Dale, over the crest
of Birdsall Wold and down the north-facing slope of Birdsall Brow as far as
the spring-line in Swinham Wood. Between Birdsall Dale and the crest of
Birdsall Brow the dyke takes the form of three 1m deep ditches between four
0.3m high banks; the overall width of the dyke measures up to 25m. As it
emerges from Birdsall Dale, the dyke runs in the bottom of a narrow slack
across a ploughed field; here, although the earthworks have been buried by a
combination of cultivation and natural hillwash, their course can be observed
from aerial photographs. North of the modern estate road to Toisland Farm, the
dyke continues as an earthwork as far as the brow of the Wold where the outer
ditches terminate. A 19th century survey of the earthworks records that these
ditches diverted to east and west becoming linear boundaries running for
several kilometres along the top of Birdsall Brow, although these have been
levelled by cultivation and it is not known how much of the former earthworks
survive below ground. The cross-dyke continues down the slope as a single
ditch flanked by two banks, having an overall width of up to 18m. Forty metres
from the top, a second westwards branch of the ditch indicates the junction of
the cross-dyke with another east-west linear boundary which has now been
levelled. The main dyke follows the field boundary northwards for a further
300m before it begins to turn gradually north-westwards, finally terminating
at the spring-line at the 160m contour.
The metalled road surface and fences are excluded from the scheduling,
although the ground beneath these features 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.

Source: Historic England

Reasons for Scheduling

Cross dykes are substantial linear earthworks typically between 0.2km and 1km
long and comprising one or more ditches arranged beside and parallel to one or
more banks. They generally occur in upland situations, running across ridges
and spurs. They are recognised as earthworks or as cropmarks on aerial
photographs, or as combinations of both. The evidence of excavation and
analogy with associated monuments demonstrates that their construction spans
the millennium from the Middle Bronze Age, although they may have been re-used
later. Current information favours the view that they were used as territorial
boundary markers, probably demarcating land allotment within communities,
although they may also have been used as trackways, cattle droveways or
defensive earthworks. Cross dykes are one of the few monument types which
illustrate how land was divided up in the prehistoric period. They are of
considerable importance for any analysis of settlement and land use in the
Bronze Age. Very few have survived to the present day and hence all well-
preserved examples are considered to be of national importance.

The cross-dyke is well-preserved over most of its length and is thought to
comprise a complete dyke. It was part of an extensive system of prehistoric
dykes which has been recorded on Birdsall Wold and has further associations
with other broadly contemporary monuments of similar type in the vicinity of
Aldro Farm. Parallels are also known from other parts of the Wolds and from
the southern edge of the North York Moors. Such associations between monuments
offer important scope for the study of the division of land for social, ritual
and agricultural purposes in different geographical areas during the
prehistoric period.

Source: Historic England

Sources

Books and journals
Mortimer, J R , Forty Years Researches in British and Saxon Burial Mounds of East Yorkshire, (1905)

Source: Historic England