 In addition to tombs that date from the friary's active period, many graves dating from the 18th through 20th centuries can be found inside the church walls.In some cases, tombstones comprise the floors of walkways and crawlspaces.Both Luke Wadding and the Four Masters (who refer to Ross Errilly in their Annals as "Ros-Oirbhealagh") record that the abbey was founded in 1351, but this date has been called into question by numerous historians.