A small rectangular oratory 7.8 m x 5.75 m in a ruinous condition with the maximum height of the walls rising to 1.85m. The proportionately thick walls (roughly 0.9 m) rest on a plinth, which projects 0.12 m externally and 0.11 m internally. The walls are faced on both vertical surfaces with coursed, dressed slabs of varying dimensions. The building originally had a steep pitched stone roof, with jointed stone shingles.

St Molaise (Laisre) founded the monastery at Devenish in the 6thc. Abbots are recorded in the 9th and 10thc. There was a community of Culdees at the site from the 10thc. An Augustinian priory was founded at Devenish c. 1130 (Ware), but it appears that the early monastery continued to function as a separate unit. In 1157 Devenish 'with all its churches' (Annals of Ulster) was burned. The two communities continued after the general suppression, but were apparently dispersed before 1607. Three 18thc. images show the building almost intact (Lowry-Corry 1936, 270-1). According to local tradition, between 1797 and 1803 the building was stripped of cut stone to flag the floor of the new church at Enniskillen, although no evidence of this is now visible in the latter structure.

The skeuomorphic form of the church suggests that it may have replaced an earlier wooden building on the site. The 1157 fire may provide a terminus post quem for the building. The style and some of the motifs used in the carving of the bases of the pilasters is similar to the fragments of the doorway found on Devenish during the 1970s. The interlace on the capital has parallels at other sites in the Erne basin including fragments from Aghalurcher and interlace on a capital at Kilmore.