Cropmarks recorded on 21st July 2022 during Royal Commission aerial reconnaissance in the 2022 drought show the characteristic outline of a previously unrecorded Roman fort. Earlier aerial photographs had recorded parchmarks of the central street of the fort without the wider marks being visible, hitherto suggesting an isolated Roman road ran through this field between Brecon and Kenchester (RR63B).

The Roman fort is aligned northeast/southwest and measures c.330m NE/SW by 150m NW/SE, enclosing 4.4 hectares. The fort survives largely intact beneath a large arable field, bounded on the southern side by the line of a disused railway, now a retail park, and with its northeast ramparts and gateways obscured beneath a hamlet of C19th-C20th housing. Cropmarks show a median street some 6m wide and 216m long, aligned NE/SW along the length of the fort, with a series of side streets springing from it. A series of smaller stony responses along the main street and side street represent the footings of buildings and other structures. The southeastern outer ditch of the fort shows well as a darker cropmark in the ripening field, but is less clear on the northwestern side. In the central part of the fort, where the ground rises slightly, the parchmark of the main road is lost suggesting it has been ploughed away with only the lower lying parts of the fort surviving intact below the ploughsoil.

Low earthworks recorded on LiDAR data and analysed by Mark Walters of CPAT suggest spread earthworks of the ramparts and ditches survive on all sides, including at the north corner in woodland adjoining housing. On the west the A4079 climbs up the site of the buried Roman rampart as it approaches a T-junction in Three Cocks. Similarly behind the houses on the northeast edge of the fort a 3-metre high earthwork is still visible on the ground which may represent part of the original rampart.

See aerial photographs AP_2022_2728 - 2752.

Toby Driver, RCAHMW, 17/11/2022

Cofnod Safle

Aberllynfi Roman fort, Three Cocks