Caer Bach, a small hill-fort at about 1,300ft above O.D. The end of a spur projecting E. from Tal y Fan rises slightly to form a rounded hillock, which is encircled by two roughly circular lines of defence. The outer is a bank of earth with an external ditch, which survives to a total height of about 10ft. A stone revetment of laid masonry can be traced on the N.W. outer face, and a slight counterscarp bank on the S. The E. side merges into the natural slope. Separated from this rampart by about 50ft. are the footings of a stone wall, much robbed, about 12-15 feet thick, built in short straight lengths. The facing, where it survives, is generally of large blocks set on their longer edges. There entrances through both ramparts were on the S.E., but are much ruined. A hut circle and be traced against the inner face of the N.W. side of the inner enclosure.