St. Mary's Abbey in Trim, County Meath, Ireland is a former house of Augustinian canons dedicated to the Blessed Virgin. The abbey was situated on the north bank of the River Boyne, opposite Trim Castle, on land given to St. Patrick who is often credited with founding the abbey. The abbey was a prominent pilgrimage site, famous for the healing power of its statue of the Virgin Mary, until its dissolution under Henry VIII during the Reformation. Little remains of the abbey except for the Yellow Steeple, the ruin of the abbey bell tower named for the yellow colour reflected by the stonework in the setting sun, and Talbot's Castle, an abbey building converted to a manor house.
The Sheep Gate is the only surviving gate of five that once provided access to Trim. The town wall and its gates were built in the 13th or 14th century. Sheep Gate may have been so named as a toll was charged here for sheep being brought in to be sold at market: in 1290, the murage and pavage tax was one penny per ten sheep, reduced to a farthing in 1308. The name could also derive from the archaic meaning of cheap, meaning "market" (cf. Cheapside). This name is not recorded before the 19th century; it may have been known as the Porch Gate, possibly from French porte ("door"), which may also give its name to the Porch Fields lying outside the city walls. The gate was locked between 9 p.m. and 4 a.m.