Glastonbury Tor is a hill at Glastonbury, Somerset, England, which features the roofless St. Michael's Tower. The site is managed by the National Trust. It has been designated as a Scheduled Ancient Monument (No: 196702).
Tor is a local word of Celtic origin meaning "rock outcropping" or "hill". The Tor has a striking location in the middle of a plain called the Summerland Meadows, part of the Somerset Levels. The plain is actually reclaimed fenland out of which the Tor once rose like an island but now, with the surrounding flats, is a peninsula washed on three sides by the River Brue. The remains of Glastonbury Lake Village nearby were identified in 1892, showing that there was an Iron Age settlement about 300–200 BC on what was an easily defended island in the fens. Earthworks and Roman remains prove later occupation. The spot seems to have been called Ynys yr Afalon (meaning "The Isle of Avalon") by the Britons, and it is believed by some to be the Avalon of Arthurian legend.[Source]