It was built between 1282 and 1311 on a hill overlooking the town, on the site of an earlier Welsh fort, with an unusual triangular gatehouse formed out of three massive polygonal towers. Initially the rear of the castle adjacent to the town was protected by the town wall but new walls were added in 1295 after the town was captured by the Welsh. It was badly damaged during a six month seige during the Civil War and by slighting in 1660
but much of interest remains. The town walls are still standing almost complete and one of the gateways, the Burgess Gate, still remains.