Reasons for Designation
Martin Down enclosures (named after a typical example on Martin Down in
Dorset), are small, usually sub-rectangular areas often covering less than
0.3ha. originally bounded by a low bank and/or fence with a surrounding ditch.
Most have a single entrance, identified by a causeway over the ditch. Dating
to the Late Bronze Age, from the tenth to eighth centuries BC, these
enclosures are interpreted as domestic settlements, and excavated examples
have been found to contain circular structures, post holes, pits, hollows and
burnt mounds, associated with fragments of querns, pottery, animal bones,
charred grain, worked flint artefacts and metalwork. In some cases, as with
the enclosure on Martin Down itself, they are associated with contemporary
field systems. They occur mainly on the chalk downland of central southern
England, although examples in Kent, Sussex, East Anglia and the Midlands are
also known. Generally constructed on the flanks of hills, they have also been
identied in valley bottoms and on hilltops. Because they are usually situated
on good agricultural land, many have been levelled by subsequent ploughing and
survive largely in buried form, often visible as cropmarks on aerial
photographs. Fewer than 15 examples have been positively identified so far.
Martin Down enclosures are thus a very rare monument type and form one of a
limited range of monuments dating to the Late Bronze Age. All examples with
surviving remains are considered to merit protection.
The Martin Down style enclosure on Thundersbarrow Hill survives comparatively
well, despite some damage caused by ploughing. Part excavation has shown that
it contains information about the landscape in which it was constructed and
about its contemporary and later use. The later hillfort also survives
comparatively well, and its close association with the earlier enclosure
illustrates the frequent utilisation of hillfort locations in the earlier
prehistoric periods. Also commonly found on hilltop locations are bowl
barrows, a type of Bronze Age burial mound. The environs of the hillfort have
also been investigated by part excavation and survey, revealing an area of
later Roman settlement and an associated field system. Together these remains
illustrate the changing function of the hilltop over nearly two millennia.
Details
The monument includes a Martin Down style enclosure and bowl barrow dating to
the Bronze Age, a later slight univallate hillfort dating to the Iron Age and
a Romano-British aggregate village and associated regular aggregate field
system, situated on a north west-south east aligned chalk ridge which forms
part of the Sussex Downs. Also included within the monument are traces of
medieval strip cultivation, a 19th century dewpond and a group of slit
trenches associated with the use of the ridge as an army training area during
World War I and World War II.
Lying near the north western edge of the monument, within the later hillfort,
the Martin Down style enclosure covers an area of c.0.49ha. Part excavation in
1985 and earlier records suggest that the roughly square enclosure, which has
sides measuring c.70m, has been largely levelled by modern ploughing but
survives as a slightly raised area originally bounded by a low bank. This is
surrounded by a now infilled ditch which survives as a buried feature c.3m
wide and c.0.6m deep. Two original entrances have been identified, formed by
c.6m wide gaps through the western and eastern defences. The excavation also
led to the discovery of fragments of bone, worked flints, a piece of antler
and pottery sherds in the ditch fills, and analysis of the latter has
suggested that the enclosure was in use during the tenth and ninth centuries
BC. The enclosure is associated with a broadly contemporary, now infilled,
north-south aligned ditch situated c.18m to the west. This is c.4.5m wide and
partly underlies the north western ramparts of the later hillfort. The roughly
circular hillfort has also been partly levelled by modern ploughing and
survives to the east largely in buried form, with some features visible as
crop marks on aerial photographs. To the west, the defences, which enclose an
area of c.1.33ha, are formed by a bank surviving as a scarp up to c.1m high.
Part excavation in 1932 showed that this is surrounded by a now infilled ditch
c.7m wide. Access to the interior is provided by two entrances through the
northern and south eastern ramparts. The northern entrance is formed by a
simple gap c.18m wide, whilst the south eastern entrance has an inturned
passageway c.9m wide. Pottery found during the excavation suggests that the
hillfort was constructed during the sixth century BC and continued in use
until the mid-third century BC. Despite some later disturbance by 20th
century army training activities and modern ploughing, the hillfort interior
will contain further buried remains relating to the use of the hillfort and
the earlier underlying Martin Down style enclosure.
The bowl barrow, known as Thunders Barrow, lies c.10m south east of the later
hillfort. The south eastern side of the barrow was disturbed by the
construction of the adjacent dewpond in 1873, which led to the discovery of
human cremation burials contained within pottery cinerary urns dating to the
prehistoric, Roman and early medieval periods. The barrow was also partly
disturbed by earth moving in 1964. It survives as a semi-circular mound c.17m
in diameter and up to c.2m high.
The later Romano-British village lies in the areas to the east and north of
the hillfort, and its structures have also partly disturbed the hillfort
ramparts. The village now survives in buried form, and topographical survey
and part excavation in 1932 identified the focus of the village as two
adjacent roughly square platforms with sides measuring c.30m, containing a
number of rectangular houses c.5m by c.3.5m. Pottery sherds and coins dating
to the years between c.50-400 AD suggest that the village was inhabited for
most of the period of the Roman occupation. Associated with the houses are a
well, a number of storage pits and two furnaces, interpreted as corn drying
ovens, one of which is situated c.70m to the north of the focus of the
village. The excavations also revealed fragments of daub, part of a sandstone
rotary quern and charred wheat grains. Further buried remains associated with
the use of the ridge at this time will survive in the areas between and around
these features.
The agricultural activities practiced by the inhabitants of the village are
represented by the contemporary field system which survives on the hillslopes
which form the southern, western and eastern sides of the ridge. This covers
an area of c.40ha. A series of lynchets, which survive as earthworks up to
c.0.5m high and as crop marks visible on aerial photographs, define the
individual fields, which are mainly rectangular, with an average size of
c.0.35ha. At least two associated trackways have been identified, with the
main route running along the ridge just to the south west of the modern
downland track which traverses the monument. Military trenches excavated
during World War One on the south western slopes and traces of medieval
cultivation, which range down the hillslope to the east of the Romano-British
village, have partly disturbed the field system. Analysis of soil samples from
the fields has indicated that the hillsides were also being cultivated during
the earlier Iron Age period.
The modern fences and the surface of the modern trackway which cross the
monument 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.
