Launceston Castle is built on a ridge that slopes from the east down to its west, where it meets a sharp incline. To the north, the ground drops away to the River Kensey. The castle comprises a curtain wall enclosing a bailey, with the remains of a north and south gatehouse. The inside of the bailey, across, contains the foundations of various buildings, including the castle's great hall. In the north-east corner is a motte, topped by a keep and the high tower. The majority of the fortifications are built from shale stone, with the detailing carried out in granite and Polyphant stone.