Abbeyderg Graveyard is located just 5km from the village of Kenagh, stands the ruins of the 13th-century Augustinian priory of Abbeyderg. The priory was founded by Gormghal Ó Cuinn, chief of Muintir Ghiollagáin, shortly before 1199. It was known as Mainisterderg or Dearg and was dedicated to St. Peter.
In 1540 it was one of five monasteries in the Annaly region that was surrendered to Henry VIII. A decade later, Shane O’Ferald (Ferrall) was granted a 21-year lease of the ‘site of the monastery of Monasterderge’.
It was largely destroyed in 1567, after the granting of a 21-year lease to a Thomas Byram, although the abbey church remained largely intact.
Originally the priory consisted of a church with a cloister area to the south, and a range of small chambers on the eastern side of the cloister. The church may also have had transept arms, giving it a cruciform plan.
It is likely that the abbey church may have been constructed with a tower over its western end. Today, only the eastern end of the chancel survives, which is where the high altar would have been located.
The altar window is comprised of a group of three gothic window openings, a design which was not uncommon in 12th and early 13th century Irish churches. Two windows also survive on the southern wall of the chapel.
The priory church is surrvounded by a graveyard with the majority of headstones dating from the 19th and 20th centuries, although a fragment of a medieval cross-inscribed grave-slab does remain.
Other archaeological features of interest in the graveyard include two circular millstones and a variety of small architectural fragments.
The abbey and graveyard are open to the public.