The Roman fort which lies west of Caerau farm, near Tirabad on the north-west edge of the Sennybridge Training Area, has long been under study. The site was previously dismissed as a Roman Fort and rejected instead classified as a fortuitous arrangement of natural and other non archaeological features by the Ordnance Survey (Source: CPAT database). Analysis of aerial photography and LiDAR by Bryn Gethin in 2010 revealed a probable square, round cornered enclosure, with an outer enclosure below, also with round corners but the status of the site remained uncertain (see Musson and Driver 2015). In 2023, vertical aerial photographs on Bing Maps, flown during the extensive drought of 2020, showed parchmarks of an upper, inner 'playing card' enclosure on the summit of the plateau, with a lower, outer earthwork enclosure with a 'playing card' form comprising an inner earthwork rampart and bivallate outer ditches.

The status of the Roman fort was finally confirmed beyond doubt in 2023 with the discovery, 500m to the south, of the denuded earthworks of a 19.7 hectare Roman marching camp from Welsh Government LiDAR. This camp lies in a classic position, recognised elsewhere in Wales, in close proximity to a later Roman fort.

Caerau Roman fort measures approximately 290m SW/NE by 250m NW/SE, enclosing 6.1 hectares. It straddles a high plateau at 280m above Ordnance Datum. It lies 3km south-east of the Abererbwll Roman fortlet on the edge of Crychan Forest.

T. Driver, RCAHMW, 24/072023

Reference:

• Musson, C., and Driver, T. 2015. Above Brecknock, An Historic County from the Air. The Brecknock Society and Museum Friends and The Clwyd-Powys Archaeological Trust, in collaboration with the Royal Commission on the Ancient and Historical Monuments of Wales. Brecknock Society. Brecon.