It sits in a now-waterless gully in the valley of Baile na hAbha, its carefully lined walls dropping 1.3 metres below the gully floor on one side and rising above it on the other, with that upper step apparently stone-faced as well. The measurements are precise enough: 3.6 metres long, just over a metre wide, open to the north-north-west. What it was actually for remains open.

The valley it occupies, known in Irish as Fothair na Manach, meaning roughly the monastic precinct or terrace of the monks, is by some accounts the most inaccessible settlement on the entire mainland of Corca Dhuibhne, the westernmost part of the Dingle Peninsula. Tradition links the place to St. Brendan, the sixth-century navigator whose legendary voyage across the Atlantic has generated centuries of scholarly and popular fascination; he is said both to have founded a monastery here and to have rested in the valley before setting out on that journey. Whether or not the monastic connection is genuine, the remoteness of the location is itself suggestive of early Christian settlement, since early Irish monks often sought out difficult, marginal terrain as a form of spiritual discipline. Despite all of this, the valley was apparently still home to three or four families at the start of the nineteenth century, which complicates any reading of the landscape; it is not clear how much of what survives on the ground reflects the ancient settlement and how much was built or altered by those later occupants. The unidentified pit, recorded by J. Cuppage in the 1986 Dingle Peninsula archaeological survey, was interpreted by an earlier scholar, Power, writing in 1923, as a sluice, perhaps a structure for controlling or channelling water when the gully still ran. That remains a reasonable guess, but only a guess.