The castle at Llanquian is thought to have originated in the twelfth century and was subsequently re-built in stone in the thirteenth. A mound, c.32.5m in diameter, showing traces of a ditch has, upon its summit, a partial bank thought to mask an oval stone wall, c.18-20m in diameter. A rectangular stone building, 9.5m northwest to south-east by 8.0m, projects from the north-west of the summit.

source: RCAHMW 1991, 263-5

J.Wiles, RCAHMW, 29 January 2003