Dinieithon Castle

or Old Cefnllys Castle

A mile or so north of the Mortimer castle of Cefnllys, are the remains of a ditched motte or ringwork, sitting high above the river Irfon, a few miles east of Llandrindod. Surviving records speak of a timber predecessor of the great castle of Cefnllys, called Dinieithon, but there is no indication of exactly where it was. It is assumed that these earthworks to the north mark the spot, but some have expressed the view that Dinieithon was a previous castle on the Cefnllys site.
OS 092630

Dinieithon was built by Ralph Mortimer around 1093, but it is said to have been destroyed around 1130 by Madog ab Idnerth, the partially-dispossessed Welsh lord of the area between Wye and Severn. The castle was certainly in existence again by 1179 but was was then superseded by the building of the masonry castle at Cefnllys in 1242.

The fortification was 60m by 42m in size and extensive earthworks remain.