Professor Aubrey Manning explores the hillside of Glastonbury Tor in this BBC documentary from 2009 

The Terraces of Avalon
Landscape Mysteries
Episode 8 of 8
One of the mysteries surrounding Glastonbury has been the origin of a series of stepped terraces on the Tor. They may have been part of a Neolithic maze, or possibly fortifications built by King Arthur on his Isle of Avalon.
Professor Aubrey Manning explores whether there is a connection between the terraces and the myths and legends which permeate this area. A new geophysical survey of the Tor helps Aubrey assess the evidence as he looks for clues in the history of the surrounding countryside. But it is the once-prosperous abbey at the base of the Tor which points Aubrey towards a link he hadn't suspected between the terraces and the Glastonbury myths.