Castell Collen

On a bluff above the Ithon at Llanyre, a mile or so from Llandrindod Wells, is a rectangular platform with banks round it. It is one of the most useful Roman sites in Wales for a reason that has nothing to do with what is standing.

The reduction

The fort was built around AD 75 during the campaigns that subdued central Wales, one of the chain running north to south through the middle of the country — Y Gaer near Brecon to the south, Caersws to the north.

Then, at some point in the second century, it was made smaller. A new rampart was thrown across the interior and the fort was reduced to roughly two thirds of its original footprint.

That reduction is visible on the ground. You can walk the outer rampart of the first fort and then the inner rampart of the second, and see exactly where the army decided it needed less space.

Very few Roman sites let you read a policy change that directly. It tells you the province had concluded that central Wales was quiet enough to thin the garrison, and it is part of a pattern repeated at other mid-Wales forts.

What is there

Earthworks, and no standing masonry. The defences are clear on most sides, with the platform of the interior and traces of buildings visible in the right light.

Excavations took place in 1911 to 1913 and again in the 1950s, establishing the plan, the sequence and the reduction. There was a bath house outside the walls, as there always was, and a civil settlement.

Why the Romans were here

The same reason as everywhere else in this county: control of movement.

There is no town and no villa anywhere in what is now Powys from three and a half centuries of Roman occupation. What there is, is a set of forts a day's march apart on the river crossings, linked by roads that let troops move between Chester and Caerleon without going round the coast.

Castell Collen holds the Ithon crossing and the route north from Brecon. That is its entire purpose.

Visiting

The site is on private farmland with permissive access. Check locally, keep to the edges of the field, close gates and do not take vehicles up.

There is no interpretation on site and no facilities. It is a short walk from the road at Llanyre.

Llandrindod Wells is a mile and a half east, and the town museum holds material from the fort.