As early as the 6th century, monastic settlements were being built in remote areas of Ireland. This small oratory is usually thought to have been built without mortar, but there is evidence that even if mortar "was never visible in the wall facings it was used as a structural medium for the interior of the wall at least." The oratory uses corbel vaulting, a technique developed by Neolithic tomb-makers. It is dimly lit, with only a tiny window opposite the entrance door. Shaped like an upturned boat, this miniature church overlooks the harbour at Ard na Caithne (formerly also called Smerwick) on the Dingle Peninsula.