Dundas Castle or Tower is a massive 15th century keep of four storeys and a flat roof, now L-plan with the addition of a later wing. A round caphouse with a rib-vaulted ceiling crowns the main turnpike stair. The corbelled-out parapet has open rounds at the corner.
The entrance at the re-entrant angle still has an iron yett. The basement is vaulted and has a stair in one corner which leads to the hall on the first floor. The castle has been greatly altered inside with brick partition walls. The main stair climbs only to the first floor. There were fine private chambers above the hall, some of them vaulted.
The Dundas family held the lands from about 1124 until 1875, and built the castle in 1424. It was besieged in 1449, and visited by both Charles II and Cromwell in 1651. The castle was abandoned when the nearby Gothic mansion designed by William Burn, was built in 1818, and later converted for use as a distillery. It is empty but in fairly good condition. The house was sold to the Stewarts in 1875.