The town is particularly notable for the myths and legends surrounding a nearby hill, rising up from the otherwise flat landscape of the Somerset Levels, which looks man-made (but isn't), Glastonbury Tor. These myths concern Joseph of Arimathea and the Holy Grail, and also King Arthur. Glastonbury is also said to be the centre of several ley lines.
The Joseph of Arimathea legend relates to the idea that Glastonbury was the birthplace of Christianity in the British Isles, and that the first British church was built there at Joseph's behest to house the Holy Grail, 30 or so years after the death of Jesus Christ. The legend also says that earlier Joseph had visited Glastonbury along with Jesus as a Child. William Blake believed in this legend and wrote the poem that became the words to the most patriotic of English songs, 'Jerusalem' (see And did those feet in ancient time).
Joseph is said to have arrived in Glastonbury by boat over the flooded Somerset Levels. On disembarking he stuck his staff into the ground, which flowered miraculously into the Glastonbury Thorn (or Holy Thorn). This is the explanation behind the existence of a hybrid hawthorn tree that only grows within a few miles of Glastonbury. This hawthorn flowers twice annually, once in spring and again around Christmas time (depending on the weather). Each year a sprig of thorn is cut by the local Church of England priest and sent to the Queen to feature on her Christmas table top.
The original Holy thorn was a centre of pilgrimage in the middle ages but was chopped down during the English civil war (in legend the roundhead soldier who did it was blinded by a flying splinter). A replacement thorn was planted in the 20th century on Wearyall hill but many other examples of the thorn grow through out Glastonbury including those in the grounds of Glastonbury Abbey.
In some versions of the Arthurian myth, Glastonbury is conceived of as the legendary island of Avalon, the word Avalon itself being an anglicised corruption of the Celtic "Annwn", the Celtic twilight world of faerie. An early Welsh story links Arthur to the Tor in an account of a face-off between Arthur and the Celtic king, Melwas, who had apparently kidnapped Arthur's wife Queen Guinevere. Geoffrey of Monmouth first identified Glastonbury with Avalon in 1133. In 1191, monks at the Abbey claimed to have found the graves of Arthur and Guinevere to the south of the Lady Chapel of the Abbey church, which was visited by a number of contemporary historians including Giraldus Cambrensis. The remains were later moved, and lost during the Reformation. Many scholars suspect that this discovery was a pious forgery to substantiate the antiquity of Glastonbury's foundation, and increase its renown.
It is also well known for the (usually) annual "Glastonbury festival", a music festival that has been likened to a British Woodstock (the festival actually takes place in the small village of Pilton, but since Glastonbury is a nearby town, it has lent its name to the event).