St Mary's Abbey was founded in 1055 and became the most powerful and wealthy Benedictine monastery in the north of England. At its peak it controlled vast landholdings across Yorkshire and competed directly with the Archbishop of York for influence over the northern church. Henry VIII's Dissolution of the Monasteries reached York in 1539, and the monks were expelled and the buildings stripped of anything valuable. What stands in Museum Gardens today — a substantial section of the nave's north wall and the outline of the chapter house — gives enough sense of the building's scale to be genuinely impressive.
The ruins are free to visit as part of the Museum Gardens and are most atmospheric in the early morning or at dusk when the crowds thin. The fragment of the great west doorway still stands to a considerable height, and in the summer months the ruins are used as the setting for the York Mystery Plays — a cycle of medieval religious dramas that were originally performed by the city's guilds and revived in the 20th century. The connection between the plays and the abbey close is appropriate: the monastery was one of the original patrons of the cycle.