This Roman site, thought to that of an auxiliary fort, is located at a critical point in the mid-Wales road system, where the Roman roads from Trawscoed, Castell Collen, Carmarthen and Brecon meet. The fort is thought to be that of Alabum, established in the 70s AD during the Flavian advance. Two later phases are represented by a reduction in its size before abandonment around AD 130. Possible traces of an extramural settlement have been recorded to the north-east and placenames below the fort to the south-east include 'Cae Bricks' and 'Tre Goch'. A possible Roman fortlet (NPRN 309669) has been recorded at Blaenos, about 1.75km to the west.

The site consists of a rectangular enclosure, measuring some 180m north-east to south-west by 140m. The enclosure comprises two sections seperated by a road which branches north from the A483 and joins it again some 400m further north-east. The enclosure's well preserved western section is a Scheduled Ancient Monument, defined by scarped banks. It is located mainly to the north and west of St Mary's Church (NPRN 103828). The eastern section extends some 70m south of St Mary's church, and is dilineated by the A483 to the east. It extends north to the point where the diverged road rejoins the A483. Historic (1888 and 1905) Ordnance Survey mapping depicts scarped banks also dilineatting the eastern section, with the A483 appearing to run along the top of the scarp. Historic Ordnance Survey mapping also depicts (with scarped banks) a further, smaller rectangular enclosure extending from the south-west end of the main enclosure. Modern development appears to obscure this feature. Modern Ordnance Survey mapping depicts the original line of the Roman road leaving the A483 (branching east of the current road) some 50m south-south-east of St Mary's Church, and continuing on a straight course for some 400m, before joining the A483 again. A third century pottery sherd from the fort and fourth century material from the vicinity suggest later Roman activity in the area, though this may simply be the result of casual losses along the road. There are fragments of Roman tile in the walls of the church.

Sources include:
James, 2000, Current Archaeology 36, pg29-30; pg33-34
James et al., 1983, Archaeology in Wales 23, pg34
Jarrett 1969, Roman Frontiers in Wales, pg95-6
Ordnance Survey, 1888, first edition 25in
Ordnance survey, 1906, second edition 25in
Ordnance Survey, modern, 1:10,000
Parry, 1984, Archaeology in Wales 24, pg51
Wilson, 1962, Journal of Roman Studies 52, pg161-162
Wilson, 1963, Journal of Roman Studies 53, pg125
Wilson 1970, Britannia 1, pg271-272
Wilson 2002, Archaeology in Wales 42, pg115.

J.Wiles, RCAHMW, 4 August 2004