Halton Castle was originally a 13th century timber-framed manor house and barmkin, which was burnt by William Wallace. In the early 14th century, John Halton added a T-plan hall house and solar block, built of reused stone from Onnvm Roman Fort. In the late 14th or early 15th century, William Carnaby founded the castle when adding a rectangular four storey tower house, probably built as a defended stronghold against attacks from Scottish raiders. Crowned by crenellations with corbelled round bartizans on the angles, the ground-floor vaulted chamber, with a northern entrance doorway and a mural stair giving sole access to the first floor, was once protected by a forebuilding. In the late 17th century, John Douglas added the eastern adjoining two storey block, this made the castle irregular in plan. The fragments of medieval walling extending westwards from the tower and some old masonry to the north of the brewhouse, probably represent the barmkin. A mile south is Aydon Castle.