Following a family visit to the Rock of Cashel yesterday, I came across this interesting paper by Peter Harbison – the full text of which contains a concise overview of the archaeological evidence for labyrinths in a Christian context.
The decoration on the north side of the base of the twelfth-century St. Patrick’s Cross on the Rock of Cashel is interpreted as a labyrinth with Minotaur on the basis of comparisons, particularly with manuscripts such as the roughly contemporary Liber Floridus of Lambert of Saint-Omer. Because of possible evil connotations of the Minotaur, the carving may have contained a symbolic message directed at traditional Irish churchmen, whose practices the ecclesiastical reformers at the Synod of Cashel (1101) would have regarded as sinful.
This labyrinth is pictured and discussed further here on the Labyrinthos site. From that site:
First noted in 1998 (Harbison, 1998), the labyrinth carved on the north side of the base of St. Michael’s Cross at the monastic complex on the Rock of Cashel has now been moved into the Hall of the Vicars’ Choral for protection. The carving, 29 inches (73 cm) in diameter, was originally interpreted as a series of concentric circles and is badly weathered, especially on its lower half, but with controlled lighting these circles can be seen to form the remains of a complex medieval-style labyrinth, probably originally of 15-circuit form, with the entrance to the left. A small carved figure at the centre of the design is surely a representation of the Minotaur. Assuming the carving is contemporary with the construction of the cross, a dating from somewhere in the early 12th century is likely, and therefore before the influential labyrinths were laid in the floors of the Gothic Cathedrals of France, but at the same time that they were appearing in Italian churches and cathedrals and in many manuscripts. Indeed, the form of this labyrinth at Cashel suggests influence from a contemporary copy the Liber Floridus of Lambert of St. Omer, likewise created in the early 12th century.