Description
The monument consists of the remains of Knockall Castle, a sixteenth- century towerhouse with late seventeenth-century additions. It was possessed by the Udny family but was temporarily captured by Earl Marischal, a covenanter, in 1639. Knockhall fell into ruin after it was accidentally burnt in 1734.
The towerhouse is situated 150m ESE of Mains of Knockhall. The building is L-shaped, the long elevations lying N and E, with a square stair-tower projecting 3.45m from the N wall. Knockhall has had a vaulted ground floor (the vault over the kitchen has collapsed), two upper storeys and a garret. The rubble-built walls stand to roof height and measure 14.05m E-W by 14.05m N-S overall, with walls about 1.2m thick. The basic fabric dates from the sixteenth century, later modifications being confined to windows, internal details and probably the N stair-tower.
The entrance, with a lintel dated 1565, is in the re-entrant angle of the W wing. Above the entrance are two empty moulded panels. This entrance is connected by a passage directly to the stair tower. Entering off the passage on the W is the kitchen, with its fireplace, sink and drain. The E portion, originally one apartment, also has a sink and drain. The upper floors have gone and the stairs are demolished. Most of the rooms are provided with garderobes. Security features include oval gun-loops, small windows and a door with a hole for a sliding bar.
The castle was also provided with an enclosed courtyard to the S, in the SE angle of the enclosure are the foundations of a fortified round tower, 4m in external diameter. This feature was latterly converted into a dovecot. The area to be scheduled is rectangular, to include the castle and associated courtyard, and measures a maximum of 25m NE-SW by 30m NW-SE, as shown in red on the accompanying map.