The outline is subcircular, roughly eleven metres east to west and just over ten metres north to south, and if you know to look for it, the wall's inner and outer revetting stones, the carefully placed facing stones that stabilise a rubble core, are still visible in places beneath the turf. A possible entrance gap opens toward the west-north-west, angled perhaps to turn a shoulder against the prevailing Atlantic wind.

High Island, or Ard Oileán in Irish, sits off the Connemara coast and is best known for its early medieval monastery, a compact cluster of oratories, enclosures, and crosses that appear in O'Flanagan's survey notes from 1927 and in Michael Herity's work from 1977. This structure sits in the monastery's immediate neighbourhood but is recorded separately, its date left entirely open. It could be contemporary with the ecclesiastical settlement, the kind of domestic or ancillary structure that often grew up around early Irish monasteries; it could be considerably later. The archaeology has not resolved the question, and the site carries no inscription or artefact to help. What remains is simply a shape in the ground, patient and ambiguous, on an island that has always demanded a certain stubbornness from anyone who chose to live on it.