Known in Irish as Lios Uamhain, meaning roughly "the fort of the cave", it belongs to a class of early medieval enclosure called a caher, a term used in the west of Ireland for a stone-walled ringfort. What makes this particular example quietly remarkable is not what stands above ground but what lies beneath it: two narrow underground passages, running at right angles to one another, buried at the centre of the enclosure.

The enclosure measures roughly 23 metres north to south and 21.7 metres east to west. Its walls have fared unevenly over the centuries. The southern sector preserves the most original fabric, with roughly coursed stonework rising to just over a metre in places, while the northern arc has been worn down to one or two courses and part of the northwest sector appears to have been rebuilt at some point. No original entrance survives. Beneath the interior, the two souterrain passages, underground chambers of drystone construction used in early medieval Ireland for storage or refuge, can still be entered through gaps left by collapsed roofing lintels. The first runs roughly north-northeast to south-southwest and measures just over three metres in length; the second extends northwest to southeast for nearly four metres. Both are narrow, less than a metre wide and under a metre high, and the second is partially choked with fallen stone. Whether they were ever connected is uncertain, as a build-up of fill separates them. Adding to the puzzle, several low grass-covered mounds occupy the interior of the caher, their origin and purpose unexplained.

The site sits close to the lakeshore and looks out across Lough Currane, a large freshwater lake that has its own considerable archaeology. The caher is heavily overgrown, and the souterrain openings are accessible only through the collapsed sections of the roof lintels, so the experience is more one of careful observation than of comfortable exploration.