The site sits on a south-facing slope with views down to Long Island and east across Skull Harbour, on ground that has been used for rough grazing for generations. It was only when reclamation work disturbed the land that the feature came properly to light: a roughly rectangular earthen platform, approximately 35 metres east to west and 17 metres north to south, retained along its curving southern edge by a drystone revetment, that is, a low retaining wall of unmortared stone, running from about 0.2 metres high at the western end to 1.6 metres at the eastern.

According to local tradition, this is the site of Scoil Mhuire, also known by its Latin form Sancta Maria de Scala, a medieval foundation combining a church and a school. It is from this institution that both the surrounding townland and the village of Skull itself take their name. The Latin word scala, meaning ladder or stairway, and its Irish equivalent, may have referred to the slope of the ground or carried a more symbolic religious meaning; the precise origin of the name has not been definitively settled. What is clear is that the place held enough significance in the medieval period to anchor the identity of the wider settlement, and that identity has persisted in the placename long after the building itself disappeared.