There's not much left of Brecon's 11th-century Norman castle, except for a couple of sturdy walls facing the intersection of the Rivers Usk and Honddu. The main part of the castle sprouted a hotel on its landward flank in 1809, and you need to ask permission to inspect it more closely.
Brecknock Castle
Parc Cenedlaethol Bannau Brycheiniog