This ecclesiastical site near Athlone was founded in the mid fifth century by St. Rioch. Of all the original buildings, only the ruins of two churches still exist.
In the northern church, the nave, transept and sacristy survive. The sacristy was added onto the church, probably during the 15th century, along with the transept and a few sound examples of medieval windows. A primitive and irregular wall surrounds the ruins of this structure.
The church located to the south is of nave and chancel design and exhibits round and pointed doors and windows. Inishbofin monastery was attacked repeatedly over the centuries by a variety of enemies, including the Vikings. Evidence of their raids in the 10th century was found here in the form of Viking bronze work from that time period.