Close to Llanfihangel-y-pennant is the native Welsh castle known as Castell-y-Bere. Constructed from stone, on top of a rocky hillock that overlooks the Dysynni Valley it was once the largest and most richly ornamented castles in Wales. Llywelyn ap Iorwerth, a.k.a. Llywelyn the Great (c. 1172 – 11 April 1240) the Prince of Gwynedd was responsible for its construction in the 1220’s.
During the war with King Edward I (17 June 1239 – 7 July 1307) of England in 1282, the castle was captured by the English and Llywelyn’s grandson Llywelyn ap Gruffydd a.k.a. Llywelyn Ein Llyw Olaf, Llywelyn the Last, and Llywelyn II (c. 1223 – 11 December 1282) was killed. King Edward expanded the castle and built a small settlement beside it. Then in 1294 Madoc ap Llywelyn, a Welsh leader, captured and burned the castle. The English King Edward I did not repair the castle because it could not be provisioned by the sea, and so it was abandoned and fell into ruin.
The castle is allegedly haunted. It has been said that ghostly screams have been heard at the castle, and sometimes at dusk the apparition of a soldier standing on watch has apparently been seen, before he fades away.