Gallarus Oratory
As early as the 6th century monastic settlements were built in remote areas of Ireland. This small oratory, built without mortar, 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 Smerwick on the Dingle Peninsula.
It is built with the stones being laid at a slight angle, lower on the outside than on the inside allowing rainwater to run off.