Lyonesse is a country in Arthurian legend, particularly in the story of Tristan and Iseult. Said to border Cornwall, it is most notable as the home of the hero Tristan, whose father was king. In later traditions Lyonesse is said to have sunk beneath the waves some time after the Tristan stories take place, making it similar to Ys and other lost la... Found on http://en.wikipedia.org/wiki/Lyonesse
In British legend, a fertile country between Land's End, Cornwall, and the Isles of Scilly, which disappeared beneath the sea. It was the birthplace... Found on http://www.encyclo.co.uk/local/20688