The church is mainly 12thc./13thc. with some later medieval additions and incorporates a plain 12thc. S doorway. This has a chamfered label on the exterior and a tall rear arch on the interior. Three courses of the E jamb of a doorway survive in the N wall of the nave. A large, shaped block, possibly an arcuated lintel, has been reset in the S wall to the E of the S doorway. The incomplete round tower ( h. 15.85 m) has a plain, round-headed doorway about 2.00 m above ground level. There is later doorway with a flat lintel at the base of the tower. No sculpture.

Gwynne and Hadcock record that St Patrick founded a monastery at Aghagower and that Senagh was Bishop. The Annals of the Four Masters record that the erenagh was killed in 1094, the Annals of Connaught record the death of an erenagh in 1233 and the killing of an erenagh in 1247.

The round tower is not mentioned in Petrie. Lalor describes it in detail, including dimensions.