Ancient Monuments

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Roman Marching Camp South East of Coelbren Fort

A Scheduled Monument in Onllwyn, Neath Port Talbot (Castell-nedd Port Talbot)

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Latitude: 51.7795 / 51°46'46"N

Longitude: -3.651 / 3°39'3"W

OS Eastings: 286201

OS Northings: 210275

OS Grid: SN862102

Mapcode National: GBR YB.Z31K

Mapcode Global: VH5G4.NJRN

Entry Name: Roman Marching Camp South East of Coelbren Fort

Scheduled Date:

Source: Cadw

Source ID: 1011

Cadw Legacy ID: GM343

Schedule Class: Defence

Category: Marching camp

Period: Roman

County: Neath Port Talbot (Castell-nedd Port Talbot)

Community: Onllwyn

Traditional County: Glamorgan


The monument comprises the remains of a Roman marching camp, probably constructed during the period of Roman conquest (AD74-78). The large embanked enclosure is typically playing-card shaped and occupies part of a broad low ridge which rises to approximately 230m OD. The camp is bounded on all sides except the east by the marshy valleys of the Camnant and Afon Pyrddin. The crest of the ridge runs almost due west from the south-east corner so that most of the interior of the camp falls gently to the north and overlooks the neighbouring Roman fort at Coelbren. The marching camp and fort are about 180m apart.

The camp is 438m long, tapering from 332 to 305m, the area being about 14 hectares. Where best preserved, in the southern half of the west side, the defences consist of a bank and ditch about 4.6m wide by 0.3m high overall, but for most of the circuit except in the south-west quarter they have been damaged by the construction of field banks on or very near their line. The rampart can be detected almost throughout the circuit, and the rounded corners (except the south-west) remain recognisable; but all details of the entrances have been destroyed.

The monument is of national importance for its potential to enhance our knowledge of the Roman conquest of Wales. The monument retains significant archaeological potential, with a strong probability of the presence of archaeological deposits and environmental and structural evidence. The monument forms an important element in the wider Roman landscape.

The area scheduled comprises the remains described and an area around them within which related evidence may be expected to survive.

Source: Cadw

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