At the summit of Moel y Gest is a hillfort which shows some resemblance to the nuclear forts of the Early Middle Ages found in Scotland. Like these, it has a court system with loops of wall and a citadel. However the fort has several peculiarities which makes it difficult to understand. For most of its perimeter, the boundary defenses follow natural features to give it good defensive potential, but at the northwestern part, where the entrance lies, it is set back from the cliff making it vulnerable to an approaching enemy who would be invisible until close at hand. The perimeter wall contains a selectively large numbers of white, quartz stones, and it is possible the fort had a religious rather than military significance.