Islay, Port An T-sruthain

RCAHMS surveyed the dun at Port an t-Sruthain in 1976 at 1:400 using plane-table and self-reducing alidade. The plan was redrawn in ink and published at the reduced scale of 1:1000 (RCAHMS 1984, fig. 120B).

NR 387 781. On the narrow summit of a rocky coastal stack 550m N of the deserted settlement of Bolsa, on the E side of Port an t-Sruthain, there are the remains of a small dun. The summit is aligned roughly NE and SW and has been appreciably attenuated by rock-falls. The sides of the stack present steep or sheer rock-faces, ranging in height from 6.5m on the landward (SE) side to as much as 9m on the NW. Relatively easy access to the summit may be obtained at the present time by way of a narrow ledge that ascends the SW side of the stack, but, because of the extremely friable nature of the rock, this is unlikely to be the original route. For the same reason it is impossible to give exact dimensions for the internal area of the dun, but in view of the amount of rubble lying at the foot of the stack, it seems improbable that it measured much more than 13m by 5m. Of the enclosing drystone wall little more now remains than the NE angle and portions of the adjacent sides. The best-preserved sector is that on the NW, which appears to have incorporated a prominent rocky outcrop running parallel to the margin of the summit. Both the inner and outer face have survived at this point, the former standing 0.65m high in three irregular courses, the latter about 0.6m in four; the thickness thus indicated is about 2m. A curious feature of the wall construction in this sector is that the extremely uneven nature of the summit made it necessary to provide a rudimentary foundation-plinth on which to raise the inner face. On all other sides the wall appears to have been destroyed by landslips. The interior, which slopes down 2m from N to S, contains no significant features, and the position of the entrance is not apparent.

RCAHMS 1984, visited May 1979