The castle was probably built by Sir Ralph Monthermer in the second half of the 13th century, or a little earlier by FitzPayn. At the end of the fourteenth century it passed into the hands of the Montacutes family. After the execution of Margaret, wife of Sir Richard Pole in 1541, it was taken over by the Crown, and then sold to Edward Woodward in 1610. He in turn sold it to Rhys Kemeys. It is not known when the castle was abandoned and fell into disrepair.
The castle was erected on a square plan with two corner, cylindrical towers in the southern curtain. The south-eastern tower today is about 14 meters high and 3 meters of internal diameter. It had at least three floors and an entrance from the ground floor and the first floor, probably on the adjacent sidewalk on the defensive walls. The defensive wall has been preserved up to a height of 4 meters. A dozen meters to the west of the south-west corner is another tower, unconnected with the circumference of the defensive walls. Its current height is about 3 meters, it is possible that it was a dovecote.
Three cylindrical towers, fragments of the defensive wall and relics of the Tudor period building, survived to the present day. The whole is overgrown with vegetation and difficult to access due to its location on private property.
Website gatehouse-gazetteer.info, Llanfair Discoed Castle.