Details

The monument includes the buried and reconstructed remains of Swarthy Hill
milefortlet. Within the sequence of milefortlets and towers along the Cumbrian
coast this one has been identified as number 21. The milefortlet was
originally of turf and timber construction and is located on the cliff top a
short distance south of the summit of Swarthy Hill. It was originally
discovered in 1968 when aerial photographs revealed the crop marks of the
milefortlet's ditch on all sides except the west where the adjacent cliff edge
provided sufficient defence. Limited excavations by Turnbull in 1990/1 found
the milefortlet to possess east and west entrances, the latter having remains
of the posts which suported a 3m square timber tower. An axial road linking
the entrances subdivided the fortlet's interior; to the south of this road
were found traces of three 5m square earth-walled buildings with an oven and
a hearth in two of the structures. To the north of the axial road a line of
five stone-packed post holes were found to represent the centreline of a
single structure running parallel to the road for virtually the full width of
the fortlet. This structure had four doors, each of which led to a separate
cubicle or room with a hearth or oven in each. The milefortlet's rampart was
constructed of sand revetted with turves and was separated from the ditch by a
flat berm up to 5m wide. Finds from the excavation included pottery dated
entirely to the Hadrianic period (AD 117-138), fragments of sandstone gaming
boards, and ironwork including nails, hobnails, a mattock, two decorative
studs and the lid of a small lead box with iron clasps.
All fence posts 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.

Source: Historic England

Reasons for Scheduling

Hadrian's Wall marks one of the frontiers of the Roman Empire. The
international importance of the surviving remains has been recognised through
designation as a World Heritage Site.
The military importance of the Tyne-Solway route across the Pennines was
recognised by the Romans in the second half of the first century AD when a
military road, the Stanegate, was constructed along with a series of forts.
There is evidence that the Tyne-Solway route was being recognised as a
frontier by the start of the second century AD, but the line was consolidated
in the early second century AD by the construction of a substantial frontier
work, Hadrian's Wall, in c.120 AD. Subsequent attempts to establish the
boundary further north, between Clyde and Forth, failed by c.160 AD. Hadrian's
Wall then remained the frontier of the Roman Empire in Britain until c.400 AD
when Roman armies withdrew from Britain.
For most of its course, the 70 miles of Hadrian's Wall running from coast to
coast comprised a continuous stone wall (which in places was first temporarily
built of turf) with permanent structures sited at intervals of one Roman mile
(milecastles) and at third of a mile intervals (turrets) between the
milecastles. At a later date, the Wall was strengthened by 16 full-size
garrison forts built either on, or close to, the Wall. To the north of the
Wall, for most of its length, lay a substantial defensive ditch and to the
south a complex of banks and ditches provided east-west communication and
demarcated the frontier zone from the province.
To the west of Bowness-on-Solway, where the Wall reached the sea, however, the
frontier had a different character and served a slightly different purpose. At
the western end of the Wall a system of milefortlets and towers, spaced
similarly to the milecastles and turrets along the Wall, extended the frontier
system for at least 27 miles down the Cumbrian coast and helped control
movement across the estuary of the Solway Firth. In places these milefortlets
and towers were supplemented by lengths of palisade fences.
Throughout its long history the Wall was not always well maintained. It was
often neglected and sometimes overrun, but it remained in use until the late
fourth century when a weak and divided Roman Empire finally withdrew its
armies from the Wall and Britain.
The frontier works along the Cumbrian coast survive as earthworks or buried
archaeological remains, the latter sometimes visible on aerial photographs.
They survive in this form largely as a result of the more ephemeral materials
of which they were built (timber and turf instead of the stone of Hadrian's
Wall land frontier) rather than because of poor survival of archaeological
remains. Components of the coastal frontier which have surviving
archaeological remains, whether visible or not, will generally be considered
of national importance.

Despite excavation of the milefortlet's interior and consolidation for public
display, buried remains of Swarthy Hill milefortlet's defences still survive
reasonably well. The monument will contribute to further study of the
Roman frontier defences along the Cumbrian coast.

Source: Historic England

Sources

Books and journals
Bellhouse, R L, 'Trans Cumb and West Antiq and Arch Soc. New Ser.' in Roman Sites On The Cumberland Coast, , Vol. LXIII, (1963), 142-3
Turnbull, P, 'Archaeology North' in Excavations At Milefortlet 21 In 1990 Interim Summary, , Vol. 1, (1991), 21-7
Other
AP No.s CCC 1595, 28 & 29, Cumbria County Council, Swarthy Hill milefortlet 21,
AP No.s CCC 3059, 23 & 22, Cumbria County Council, Swarthy Hill milefortlet 21,
RCHME, Cumberland Coast Events Record, (1995)
Turnbull,P., Excavations at Milefortlet 21 in 1990 Second Interim Summary, 1992, In Cumbria SMR No. 837

Source: Historic England