Monument record MHG1894 - Ring of Castlehill

Monument, 'Ring of Castehill'. Diameter: 70m. A circular monument in marshy surroundings, consisting of two banks and a ditch running between them. A third bank and accompanying ditch runs around the W side. A causewayed entrance is visible at the N end. It is cut by a modern drainage ditch.
R J Mercer, NMRS MS/828/19, 1995

Ring of Castlehill is as described by the previous authorities. The site may also be compared with the ring works of Strathnaver (NC64SE 30), Borgie (NC65NE 1), Lairg (NC50NE 38) and Suisgill (NC92SW 13).
Visited by OS (JB) 6 May 1982

A medieval ring-work of either Norse or Norman origin. The counterscarp bank shows traces of stone walling on its outer face in vicinity of entrance on N. This may be merely an entrance feature, but fact that outer side of bank is slightly higher than inner suggests that it may be remnant of a revetment to whole outer face.
If earthwork is of Norman origin, it may be seen as a campaign castle related to William the Lion's activities in area (1165-1214). If it is Norse a parallel may be found in possibly primary earthwork of Cubbie Roo's Castle on Wyre (HY42NW 5).
E Talbot 1979

Ring of Castlehill (NR) OS 6" map (1970)

The Ring of Castlehill, a roughly circular definsive earthwork, is generally as described by RCAHMS. The breastwork around flat
top of central mound is no longer visible in NE and SW arcs. The ditch still contains water and outer bank is cut in S by a modern ditch. Another concentric modern ditch skirts outer bank along N, E, S sides. Across entrance, at outer bank, there is slight bank of earth 0.2 m high, purpose of which is unknown. The earthwork may be site of castle.
Resurveyed at 1:2500. Visited by OS (NKB) 15 September 1965

A circular green mound rising from a now-drained moss. 'A ditch some 35 ft in width encircles it at its base, having on outside a bank, formed of upcast, some 2 ft 6 ins in elevation above the natural level, and 11 ft across top which is flat. The ditch has a depth of some 5 ft below level of top of this outer bank, and of 8 ft 2 ins from top of breastwork which crowns scarp. The breastwork, which seems to be an earthen mound, is c8 ft thick at base and some 2-3 ft high on inner side; diameter of interior is some 94 ft. The entrance has been from N, from which direction continuity of ditch is interrupted by an approach over unexcavated ground some 15 ft wide. There is no stonework visible through turf with which the construction is covered, but at one or two places near base of scarp on W, rock protrudes, indicating that a natural elevation has been utilised. The ditch was probably wet, bottom being considerably below the natural level.' RCAHMS 1911, visited 1910