Colliston Castle is a 16th Century Z-plan tower house of three storeys and an attic. It consists of a main block with round towers, one corbelled out to square, projecting at diagonally opposite corners. The walls are harled and pink-washed, and are pierced by many gunloops and shot-holes. The parapet and open rounds are modern, being additions of 1894-5, when the entire upper storey was altered. Carved stones built into the front walling may have come from a Culdee chapel nearby. The windows were enlarged in the 18th century. The entrance is at the foot of the main tower, flanked by gunloops. The basement is vaulted, and contained the kitchen; a wine-cellar, with a stair to the hall above, now built-up; and other cellars. The original turnpike has been replaced by a scale-and-platt stair in a projecting tower. The hall, on the first floor, has been altered.
The property belonged to Arbroath Abbey, but was granted to the Reids in 1539, who granted it to the Guthries, who built the castle. It was sold in 1691 to the Gordons, then in 1721 to the Chaplin family who held it until 1920. The property then passed through several families, and the building is still occupied.