Glastonbury Tor

Glastonbury Tor is a tor near Glastonbury in the English county of Somerset, topped by the roofless St Michael's Tower, a Grade I listed building. The site is managed by the National Trust and has been designated a scheduled monument. The Tor is mentioned in Celtic mythology, particularly in myths linked to King Arthur, and has several other enduring mythological and spiritual associations.

The conical hill of clay and Blue Lias rises from the Somerset Levels. It was formed when surrounding softer deposits were eroded, leaving a hard cap of sandstone exposed. The slopes of the hill are terraced, but the method by which they were formed remains unexplained.

Source: Wikipedia