Y Gaer, Brecon

Two and a half miles west of Brecon, on a low spur between the Usk and the Yscir, is the best Roman site in Powys.

It was built around AD 75, during the campaigns that finally subdued the Silures, and it was built for cavalry — an ala of around five hundred mounted men, which was a substantial and expensive garrison for an auxiliary fort. That tells you the army expected trouble here and expected to have to move fast across country to deal with it.

Wheeler

Mortimer Wheeler excavated the fort in 1924 and 1925, early in a career that would take him to Maiden Castle, Verulamium and eventually the Indus valley. The report he published in 1926 established the fort's plan, sequence and garrison and is still the foundation of what is known about it.

He worked here partly because the Roman military occupation of Wales was then very poorly understood, and Y Gaer became one of the sites that defined how the frontier was read.

What survives

Stretches of the stone rampart, and — unusually for Wales — parts of the gate structures standing to a reasonable height. Three of the four gates are identifiable. The internal buildings are not visible; the interior is under grass and grazed.

The fort was reduced in size at some point during its life, which is a pattern repeated at Castell Collen near Llandrindod and suggests the province thinning its garrison as central Wales settled.

The fort is often given the Roman name Cicucium.

The wider picture

Y Gaer sits on the road running north towards Castell Collen and south towards the Usk valley and the coast. The spacing of the Powys forts — Y Gaer, Castell Collen, Caersws, Forden Gaer — is roughly a day's march, on river crossings, and it is the clearest possible statement that Rome treated this country as a corridor to be controlled rather than a place to be settled.

In three and a half centuries there was no town and no villa of consequence anywhere in what is now Powys.

Pen y Crug, the Iron Age hillfort on the ridge above Brecon, is a couple of miles east and makes the point that the Romans were choosing a position other people had already chosen.

Visiting

The fort is on private farmland with permissive access; check locally before going, keep to the path and close gates. There is no car park at the site and the lanes are narrow.

Material from Wheeler's excavations is held at Brecknock Museum in Brecon, which is the sensible place to start.