A near-square embanked enclosure, 25m across, with rounded corners and a north-facing entrance gap lies on gently sloping ground just south of the crest of a mountain ridge. Excavations in 1960 established that this is a minor Roman military work and identified a turf-built bank, but no ditch, presumably because of the rocky ground. At the entrance four great posts are thought to have supported a tower. The interior was roughly metalled and was divided by a central roadway, but no trace of buildings was recovered, though these could have rested on sleeper beams. In spring 2007 the interior showed signs of three shallow parallel ridges.

The only dating evidence comes from fragments of a black-burnished jar dating to the late second to early third centuries, but this probably doesn't indicate the date of the site's establishment.

The site can be compared to the milecastles of Hadrian's Wall. These had gate towers and building ranges either side of a central roadway. The milecastles are thought to have held garrisons of between eight and thirty two soldiers.

Sources: Putnam in Montgomeryshire Collections 57 1961-2 (1963), 33-41;
Jarrett, 'The Roman Frontier in Wales' 2nd edition (1969) 143-4.

John Wiles, RCAHMW, 16 April 2007