This monument consists of a simple tower and the remains of associated buildings.
The tower is oriented WNW-ESE and measures roughly 15m by 10m. The entrance is in the middle of the east wall and first floor level, the ground floor having two window slits but no door. The first floor contained the hall with a fireplace in the north wall and windows one window in each of the north, south and east walls. Access to the level above was by a mural stair rising to the south of the entrance passage. Local tradition holds that the castle was never finished, it is therefore possible that the mural stair rose to a second floor rather than a wallwalk.
The castle was built by Uisdein (Hugh) MacDonald in the second half of the sixteenth century. Uisdein was notorious pirate and marauder who was finally captured after the discovery of his plot to kill Donald Gorm, chief of MacDonald, at Caisteal Uisdein.
While there is no record of occupation of Caisteal Uisdein after Uisdein's capture, nearby, to the North of the castle, are the visible remains of three buildings which are probably later than the tower. The closest building, visible only as turf covered footings is on the same rock platform as the tower. Two other buildings lie below the summit and consist of turf topped wall standing up to 1m high.
The area to be scheduled includes the remains of the tower, the three lesser buildings mentioned and an area around them which may contain evidence of the construction and use of the site. The area to be scheduled is defined to the W and S by the high water mark, to the E by a line 10m out from the E wall of the tower and to the N by a line 30m out from the N wall of the tower and by the line of a burn. The area is irregular in shape, measuring at its greatest extent roughly 70m NNW-SSE by 50m, as marked in red on the accompanying map extract.