Cistercian Abbey ruins, (Church Street), Greyabbey, Newtownards, Co. Down, BT22 2NQ

Extensive early gothic ruins of a 13th-century Cistercian abbey with 15th-century additions, located north-west of the village of Greyabbey. The abbey is built of rubble and preserves significant remains of the cruciform church to the north and refectory to the south, with foundation ruins of the sacristy, chapter house and day room between them.

The west gable of the nave is largely intact, featuring a low pointed arch doorway with dog's tooth ornamentation and a 17th-century bellcote. The north and south walls of the nave retain many pointed arch window openings, as does the chancel gable. The south wall of the nave is supported on three large flying buttresses, added as a safety measure around 1907. The tower or crossing section between the nave and chancel still has remains of large equilateral arches set on corbels. Inside the nave are many memorials to the Montgomery family, dating back to the 1600s. A pointed arch sedile (seat for priest) recess is set in the south wall of the chancel next to a smaller piscina recess for washing vessels. A 13th-century sandstone effigy of a lady is set in a recess in the north wall of the chancel, with a much damaged effigy of a knight in the south chapel attached to the east of the north transept. Substantial portions of the west wall of the refectory and the south gable remain standing, with large pointed arch lancet window openings in the gable. A graveyard to the north of the church contains many varied headstones dating from the 1630s onwards.

The abbey was founded in 1193 by Affreca, daughter of Godred, King of Man, and wife of John de Courcy, the Norman conqueror of eastern Ulster. The church was originally called the Abbey of St. Mary of Jugum Dei or 'Yoke of God', with the name 'Greyabbey' being a later reference to the off-white habits worn by the Cistercians. It may have been a daughter house of Holm Cultram abbey in Cumbria. Architecturally, it is the first fully gothic style building in Ireland, with pointed rather than round-headed window and door openings. The church is said to have been founded as an act of thanksgiving by Affreca for a safe landing after a storm at sea.

During the 14th century, Greyabbey came under the protection of the O'Neills of Clandeboy, who appear to have reroofed the chancel and inserted two traceried windows, probably in the 15th century. In 1541 the Henrican Reformation reached Greyabbey and the monastery was dissolved. The abbey lands were granted to Gerald, Earl of Kildare, but in 1572 they were seized by Sir Brian O'Neill of Clandeboy, who burnt the buildings for fear they would be fortified against him by Queen Elizabeth. In 1607 Greyabbey and its estates were granted to Sir Hugh Montgomery, and branches of his family have lived on the estate ever since. During the 17th century the nave was reroofed and used as a parish church until 1778, when a new church was built just to the north-west. In 1907 the Montgomery family gave the abbey to the Commissioners of Public Works, who excavated the site and strengthened the bowed south wall of the nave. The abbey is now in the care of the Environment and Heritage Service and is a Scheduled Monument.

The graveyard to the north contains many headstones dating from the 1630s onwards, including that of Reverend James Porter, minister of Greyabbey Presbyterian church, who was executed in 1798 for supposedly treasonable activities.