There are five medieval churches and three castles in the area. Most important is Oughter Ard, a seventh-century monastery associated with saints Briga (feast day 21 January) and Derchairthinn (feast day 8 March) and site of a round tower. Recent research has estimated that the ruined church there dates to 1350, not 1609 as previously believed. It was the site of a Royal Manor. Whitechurch, (Ecclesia Alba, named for the Carmelite order) was granted 1320, and enfifed in 1508. A single headstone is the only reminder of the church of Castledillon, (1000), once a parish of its own. The graveyard beside another disappeared church at Clonaghlis, (pre 1206) is still in use and is associated with female saints Fedhlim and Mughain. Castlewarden (c1200) church has disappeared. Reeves Castle, on the Celbridge road, was built in the 14th century.