2002:0445 - MAHEE CASTLE, Mahee Island, Down

Excavation was undertaken at Mahee Castle on Mahee Island in Strangford Lough before a programme of restoration work by the Environment and Heritage Service: Built Heritage. Mahee Castle is a ruined late 16th-century tower-house on the northern shore of Mahee Island, close to the causeway to Reagh Island. The tower-house is built on an artificial terrace cut into the north-eastern end of a drumlin. The back of the terrace is retained by a revetment wall c. 4m to the south-west of the tower-house.

To facilitate the programme of restoration work, excavations had been carried out at the site during 2001 by Ruairí Ó Baoill (Excavations 2001, No. 315). Approximately two-thirds of the area between the revetment wall and the tower-house, as well as part of the interior of the building, was excavated in 2001, and artefacts ranging in date from the late medieval period to the 20th century were recovered. The primary aim of the 2002 excavation was to dig the remaining unexcavated area between the revetment wall and the tower-house so that the restoration work at the site could be completed. Excavation took place between 6 August and 12 September 2002 on an area of upstanding deposits, c. 4m by 4m, at the western end of the small yard formed by the revetment wall and the back of the tower-house. This block of deposits did not extend as far as the tower-house, as a small trench, c. 1.25m wide, had been excavated immediately adjacent to the back wall of the tower-house during the 2001 excavations.

Underlying a sequence of modern deposits was a complex of dumped and tumbled stone layers, including a spread of gravel and shell immediately adjacent to the revetment wall that appeared to be the same as that in the cement/mortar used to repair the wall during Lawlor’s restoration work at the site during the 1920s. Underlying this complex of dumped and tumbled stones was a localised spread of sandy clay loam overlying a small, square area of cobbling of uncertain purpose that was set into a clay loam bedding immediately adjacent to the revetment wall. Other deposits underlying the localised deposit of sandy clay loam included a spread of apparently redeposited boulder clay and a localised deposit of hill-wash. The precise date of these features and deposits underlying the sandy clay loam is, at present, uncertain. Potentially, they range in date from the 17th to the 19th century; however, they all post-date the ruination of the tower-house, as they overlay the sequence of deposits that represent the principal tumble or collapse of stones derived from the tower-house and possibly the revetment wall.

The sequence of deposits representing the main tumble of stones from the tower-house is provisionally interpreted as representing several discrete episodes of collapse rather than a single catastrophic or demolition event. It consisted of a heterogeneous complex of frequently concreted deposits of angular stones of various sizes, lime mortar and charcoal that included several lenses of hill-wash, which overlay an unconsolidated deposit of lime mortar and mixed stones, which in turn overlay a layer of large subangular stones that increased in thickness toward the tower-house. It is possible that the unconsolidated deposit of lime mortar formed in situ as rainwater percolated through the sequence of deposits and dissolved, and then transported downward, lime mortar from the overlying collapse and tumble deposits, which then precipitated out immediately above the relatively impervious layer of large stones. An almost complete sandstone window jamb was recovered from the deposit of lime mortar and mixed stones. The relatively unweathered condition of the jamb, coupled with the softness of the sandstone, suggests that it had not been exposed to the elements for a long period before its deposition. This observation suggests that the period between the construction of the tower-house and its falling into ruin was not great.

Underlying the deposit of large subangular stones was a thin dump of redeposited boulder clay and a localised spread of hill-wash that contained no finds and only a few flecks of charcoal. These two deposits are provisionally equated with the period of abandonment of the tower-house before its falling into ruin. These ‘abandonment’ phase deposits overlay a thin but extensive, charcoal-rich, loamy deposit that represents an occupation deposit. This occupation layer was the last deposit to butt up against the revetment wall, and its excavation revealed two small pits, one of which cut through the fill of a large pit that had been deliberately backfilled with large boulders so that the revetment wall could be built across it. The large boulders making up the fill of this pit had settled after the construction of the revetment wall, causing the wall partly to slump and subside. Both the large pit and one of the smaller pits cut the fill of a linear drain. The fill of this drain appeared to have accumulated relatively slowly, suggesting that the revetment wall is a secondary feature that post-dates the initial construction of the tower-house, possibly by a significant period. The revetment wall itself is filled with a rubble core, redeposited boulder clay and loamy hill-wash deposits. It is faced only on its north-eastern side (which faces the back wall of the tower-house), and its lowest course is slightly stepped out and laid directly onto the truncated surface of the boulder clay. The linear drain apparently cuts through a now incomplete, roughly metalled surface impressed directly into the truncated surface of the boulder clay, which forms the earliest horizon on the site. The roughly metalled surface is presumably contemporary with the initial construction of the tower-house.

In line with conditions of Scheduled Monument Consent, the roughly metalled surface and the revetment wall were not excavated but preserved in situ. In addition, only part of the fill of the large pit underlying the revetment wall was excavated, to prevent the wall from being further undermined. A wide range of artefactual material was recovered during the 2002 excavations, including pottery, metal artefacts, glass, worked stone and animal bone. A number of the pottery sherds were associated with several of the early features and deposits.

Belfast BT7 1NN