Home» Monastic Sites» Roscommon» Inishmore Monastery, Lough Arrow Inishmore Monastery, Lough Arrow Roscommon Unknown Ruins About This Site ‘Monastery’ — order, foundation and period unknown Historical Information Alternative Names: Killadoon Other Sites in Roscommon Achonry Abbey 'Abbey (in ruins)' Learn More Achonry Monastery Early monastic site, founded 7th century by St Finnian of Clonard; diocesan cathedral 1152 Learn More Aghacurreen Mass Rock At the crest of the E-facing slope of a NW-SE ridge, at the SE end, and just 9m SE of… Learn More Aghanagh Monastery Early monastic site, founded 5th century by St Patrick for Bishop Manus (Maine) and Gentene Learn More