1990:089 - RATHLACKAN, Mayo

A five week excavation was undertaken at this site funded by the Office of Public Works on the recommendation of the National Committee for Archaeology of the Royal Irish Academy. The excavated site is part of a complex of seventeen 'house sites' of various shapes and sizes and eleven megalithic tombs scattered throughout a pre-bog stone-walled field system in an area of four square miles. The purpose of the excavation was to attempt to establish the relationship of these different elements of the prehistoric landscape to each other.

The particular site chosen for examination consisted of a field wall forming a D-shaped enclosure, 20m in diameter, attached to the side of a court tomb and which enclosed a small house site. The tomb consisted of a well preserved long cairn with the tops of some orthostatic stones protruding through the top indicating a probable two chamber design. The possible remains of a court were evident facing eastwards, while the enclosure was attached to the northern side of the cairn. The excavation examined two areas - the junction of one of the ends of the enclosure wall with the cairn and also the house structure.

The junction of the tomb and wall had been completely masked by collapsed stones and by peat growth so a 5m wide portion of the cairn at the junction was examined. After removal of the collapsed stones a very well built drystone kerb retaining the cairn was revealed. This consisted of horizontally laid thick slabs and blocks of sandstone, and one vertically set slab, surviving to a maximum height of 0.7m, but judging from the amount of collapse may originally have stood to twice that height. The stones varied in thickness up to 0.25m and in length to over 2m. The enclosure wall had a facing of small horizontally laid sandstone slabs best preserved on the west side, and this also survived to a maximum height of 0.7m and had an original width of between 1m to 1.5m. It could be clearly seen that the wall was built prior to peat growth up against the kerb of the tomb but before collapse from the cairn. As the major collapse from the cairn had also occurred before peat growth, it seems likely that the enclosure, although built after the tomb, was probably contemporary with the use of the tomb.

The excavation of the house site within the enclosure revealed a square shaped structure approximately 2.5m-3m wide internally with a stone wall foundation mostly collapsed inwards. The entrance faced south-east in the centre of one side and was marked by a low flat topped threshold stone 0.82m long and 0.1m thick. This was approached by a pathway of five closely spaced flat sandstone slabs. In the centre of the structure there was a hearthstone cracked by heat and completely covered by a large quantity of charcoal. Surprisingly the only finds from the house were a few pieces of possibly worked chert although a good quality flint core and a flint flake were found nearby. The interior of the structure, however, was not completely excavated.

The nature of this structure was not clear before excavation; however, its small size, its closeness to the tomb and the scarcity of habitation refuse within may indicate a function perhaps connected with the rituals of burial within the tomb rather than as a normal domestic dwelling.

Overall the excavation was successful in establishing the relationship of the enclosure to the court tomb and in providing dating material from the house structure. The dating evidence in particular will be important in establishing a context for the whole complex of sites forming this rich prehistoric landscape.

Ballycastle, Co. Mayo