The monument consists of the remains of a castle which dates from the late 16th and early 17th centuries.
The fortification is situated on an island about 350m from the SE shore of Loch Gorm. The roughly circular island measures a maximum of 48m from NE-SW. The monument occupies the central area of the island and stands to a height of c.2.4m. The castle has a quadrangular layout incorporating boldly projecting roughly circular bastions at the angles. The fortification measures 20.5m from N-S over the
curtain wall by 17m transversely and the drum bastions vary between 5.5m and 6m in average diameter. The curtain walls and towers are of drystone boulder construction and portions are reduced to the rubble core. A depression towards the S end of the E wall may indicate the position of an entrance. This corresponds with a gap in the arc of walling (1m thick) that protects the E quarter. There are vestiges of earlier building phases on the SE and SW bastions. The curtain wall is turf backed and the interior structure, which is organised into three drystone constructed apartments, reaches the same surviving
height as the wallhead. The main rectangular building is orientated NW to SE. Adjoining its NW angle is a smaller sub rectangular annexe aligned in the same plane and floored at a slightly higher level. There is another elongated building with turf covered drystone walls aligned NE-SW to the SE of the principal building.
The area to be scheduled is approximately circular and measures a maximum of 50m in diameter, centred on the castle and including an area of land surrounding the castle in which evidence of activities associated with its construction and use may survive, as shown in red
on the accompanying map.