Local tradition holds that beneath that tangled growth lies a souterrain, an underground stone-lined passage or chamber, the kind typically associated with early medieval settlement and used variously for storage, refuge, or both. Whether that passage is intact, collapsed, or something in between remains, for now, a matter of tradition rather than confirmed record.

The site is a rath, a type of circular enclosed farmstead built in Ireland largely during the early medieval period, roughly between the fifth and twelfth centuries. Such enclosures were defined by earthen banks and ditches, and this one sits on a low ridge with wet ground dropping away to the south and north, the southern edge extending roughly 200 metres to the shores of Cloonturnaun Lough. The platform measures approximately 25 metres in diameter and is defined by a scarp, a stepped earthen face, rising to around 1.5 metres on the western side. The outer face of this scarp is stone-faced, and a low stony rim runs along the upper edge between the north-east and north-west arcs, where it has been absorbed into a later property fence. A farm lane just over three metres wide skirts the south-western arc. The site appears by name on Ordnance Survey six-inch maps from both 1838 and 1917, recorded as Lisnamucka, which suggests it was a recognised local landmark across those intervening decades. A second rath lies approximately 300 metres to the east, making this part of the Mayo landscape quietly dense with early medieval survivals.