Lismore, Sean Dun

NM83NW 2 8448 3996

(NM 8448 3996) Sean Dun (NR)

OS 1:10,000 map, (1975)

On a rocky headland on the east coast of Lismore, are the wasted remains of a dun and a later enclosure. The site affords great natural strength being defended on the south and east by precipitous cliffs and by a steep-sided gully on the north. On the west, gentle slopes offer relatively easy access.

The dun, built on the summit of a low knoll crowning the headland, is roughly circular on plan and measures about 14.8 metres in internal diameter. The wall, severely reduced by stone-robbing, appears now as an overgrown bank of stony debris 1.2 metres high and 5.5 metres in maximum width, though the survival in situ of a single inner-facing stone on the SSW as well as several short stretches of the outer face elsewhere, indicate that the original wall thickness was about 4.1 metres. The entrance faces WSW and was about 1.5 metres wide. Part of the passage wall and the inner corner stone on the north side are still visible. Round the base of the knoll on the south and west, there has been an outer wall, represented now, for the most part, by a grass grown, stony scarp, at the foot of which several outer-facing stones remain in position. The best preserved portion of this outwork is at the north end where it stands to a height of 1.2 metres. The wall is interupted for a gateway diagonally opposite the dun entrance. A large earthfast boulder which lies immediately SW of the gap in the debris probably indicates the position of one of its passage walls.

The enclosure, an irregular oval on plan, is situated on a level shelf immediately below the dun on the west. It has measured about 14 by 12.2 metres within a wall now reduced to a grass-grown stony bank 1.5 metres wide and 0.3 metres high. The entrance was probably on the west where a large stretch of the wall has been destroyed by cultivation. A line of four earthfast blocks of stone near the centre of the interior may represent part of the foundations of some recent structure, possibly associated with three adjacent clearance cairns, two of which overlie the site of the enclosure wall. The date and purpose of the enclosure are not known but since it virtually blocks the entrance in the outwork, it is likely that it is secondary to the dun and its defences.

RCAHMS 1975, visited May 1968.

As described.

Surveyed at 1:10,000 scale.

Visited by OS (R D) 22 January 1971.