The river Abbert is a major east bank tributary of the river Clare, joining it some 10 km. south of Tuam, Co. Galway. Typically, the Abbert is a sluggish, meandering stream flowing over the boggy, flat limestone lowlands between 30 and 70m O.D. Although the drift cover – chiefly angular limestone fragments in a silty matrix – is rarely more than 1 – 2m deep, exposures of the underlying d2 limestones are infrequent. Over large areas, the bedrock is masked by raised bog and further to the east by fluvio-glacial deposits.
Entrance to the Cave
Near Ballyglunin House, the Abbert river loops south for approximately one kilometre. Within this loop and in the grounds of Ballyglunin House is the entrance to the cave – some 50m north of the river asnd 5.4m below river level.
The only known entrance to the system is a circular tunnel 2m. in diameter and at the outfall of a sluice which conducts water from the river via a turbine to the cave. At the entrance the water drops 5m. into the cave itself. The cave continues upstream beneath the sluice for a short distance and it is probable that the present entrance is simply a collapse into a pre-existing passage. The upstream section is blocked by flowstone within a short distance.
Mapping and Exploration
Ballyglunin Cave was explored and mapped between November 1971 and September 1972, a total of 1287m. of passage being surveyed extending over a vertical range of 17.3m. The full plan survey together with selected passage cross-sections is shown in Figure 2. Figure 3 shows the cave in relation to surface features. Both the morphology and hydrology of this cave are extremely complex and unlike those of any other cave in Ireland.
Basically, the cave is a network of conduits developed within the main jointing patterns at 010 degrees and 160 degrees. Follow the link for more information.