Offshore , midway between Land 's End and the Isles of Scilly , is the supposed location of the mythical lost land of Lyonesse , referred to in Arthurian literature , of which Tristan is said to be a king .
Offshore , midway between Land 's End and the Isles of Scilly , is the supposed location of the mythical lost land of Lyonesse , referred to in Arthurian literature .