Clones Abbey, Monastic complex on Abbey Street in Clones, Ireland.

Clones Abbey is a monastery on Abbey Street in Clones featuring a round tower about 51 feet tall and several ecclesiastical structures in Romanesque style. The site includes ancient burial grounds and a stone sarcophagus from early monastic periods.

St. Tigernach founded the town and abbey in the 6th century, dedicated to Saints Peter and Paul. Fire destroyed it in 836, 1095 and 1184. Hugh de Lacy razed abbey and town in 1207, and the English rebuilt both five years later, adding a castle. Henry VIII's suppression of the monasteries in the 16th century ended the settlement; by the 17th century the abbey was a ruin, though solitary monks stayed in the area into the 18th century.

A 10th-century high cross displays biblical scenes carved into stone, showing the skill of medieval craftspeople. Visitors can trace these carvings and understand the effort required to create such detailed religious artwork.

The round tower stands on Abbey Street and is visible from Cara Street; the abbey itself is on McCurtain's Street. Look for the single cut stone with a haloed cross on the exterior wall opposite the surviving window, easy to miss. The tower is roofless and now about 51 feet tall, so its masonry is best examined from ground level.

On the exterior wall opposite the abbey's single window, a cut stone bears a cross with a halo, in the manner of an Irish Celtic cross. Nothing similar appears on churches of the period elsewhere, and its purpose is still debated. The mark is easy to walk past.