The Once and Future Island

I stood, looking up at Glastonbury Tor from the Somerset levels. This flat coastal plain has been drained since the Middle Ages – a patchwork of water meadows and drainage canals, which, before, was a fenland landscape of reed swamp and willow.

Glastonbury itself has been inhabited since the iron age, and the tor is believed by many to be the Isle of Avalon of Arthurian legend, rising from the wetlands in the days before the fenlands were drained.

But being so low lying these meadows are vulner...