The tor is managed by The National Trust. Even after the wetlands were drained by the Monks of Glastonbury Abbey by their vast network of drainage canals, the risk of flooding on the plain meant that farm land was at a premium for anything other than grazing cattle. The most likely explanation is medieval strip farming. Others attribute the terraces to natural ruts formed everywhere on grassy slopes by generations of grazing animals, which are slow to disappear if the grass cover is left undisturbed. Some believe that this formation is the remains of an ancient, perhaps neolithic, sacred labyrinth. The slopes of the tor appear to be quite regularly terraced. The spot seems to have been called Ynys yr Afalon by the Britons, and it is widely believed to be the Avalon of Arthurian legend. Earthworks and Roman remains prove later occupation.

The remains of a lake-village were identified in 1892, showing that there was a Celtic settlement about 300 - 200 BC on what was an easily defended island in the fens. The plain is actually reclaimed fenland out of which the tor rose like an island, but now, with the surrounding flats, is a peninsula washed on three sides by the river Brue. The tor has a striking location in the middle of a plain called the Summerland meadows, part of the Somerset Levels.

'Tor' is a local word of Celtic origin meaning 'conical hill'.

Glastonbury Tor is a high teardrop-shaped hill at Glastonbury, Somerset, England, with its only standing architectural feature the roofless St Michael's Tower of the former church.

Was glastonbury tor an island