Glastonbury Abbey is a monastery in Glastonbury, Somerset, England. Its ruins are open as a visitor attraction.
The abbey was founded in the 7th century and enlarged in the 10th. It was destroyed by a major fire in 1184, but subsequently rebuilt and by the 14th century was one of the richest and most powerful monasteries in England.
From at least the 12th century the Glastonbury area has been associated with the legend of King Arthur, a connection promoted by medieval monks who asserted that Glastonbury was Avalon.