Ross Errilly Abbey is the finest and best preserved medieval Franciscan foundation in the country. It was built by Sir Raymond de Burgo in the 14th century, and the majority of the surviving fabric is of the 15th and 16th century date. The remains include a nave, chancel, a sacristy, mill, brew house and an extensive kitchen area. There are also a fish tank, dormitory, refectory and two cloisters, one of which has a cloister arcade. There is a guest house, priors apartments and several other buildings of uncertain use. A narrow 15th century tower occurs at the junction of the nave and chancel and this is of five story's. A north transept and a later side chapel also occur. Extensive earth works also survive alone with the remains of a gate house, Several side chapels occur.

The friary was abandoned by the monks in 1753, but still remains largely intact and is well worth a visit.