Glastonbury Abbey was a monastery in Glastonbury, Somerset, England. Its ruins, a grade I listed building and scheduled ancient monument, are open as a visitor attraction.
The abbey was founded in the 8th 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. The abbey controlled large tracts of the surrounding land and was instrumental in major drainage projects on the Somerset Levels. The abbey was suppressed during the Dissolution of the Monasteries under King Henry VIII of England. The last abbot, Richard Whiting, was hanged, drawn and quartered as a traitor on Glastonbury Tor in 1539.
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. Christian legends have claimed that the abbey was founded by Joseph of Arimathea in the 1st century.