The several early Celtic settlements on the Island of Lough Erne are all sited on the south east slopes near the water's edge.  So on Devenish the lovely Romanesque eleventh century stone Priory called "Teampall Mor" lies close to the lough. Devenish was an ancient burial site of Irish kings. The "Teampall Mor" grounds were much sought after as a place of burial. Among the ruins are interesting grave slabs of the Maguires, who where the local rulers for many centuries.

The stone coffin of St. Molaise was found buried near the building known as St. Molaise's House. It is known locally as the Wishing Bed or The Saint's Bed and people lie down in it, repeat a prayer, make a wish or pray for healing. On the corners St. Molaise's House are projecting pilasters which show the remains of lovely Romanesque carving. It retained its high-pitched stone roof until the eighteenth century, when the roof was removed and used as flagstones in the Enniskillen Cathedral. The present ruin dates from the tenth century, built on the site of St. Molaise's original stone house, which he preferred to the customary mud-and-wattle bee-hive houses of this period.