According to Cornish legend, Lyonesse was a land located to the west of Lands End and disappeared in 1099 due to a storm which caused a great flood. Lyonesse was said to be a grand place with fine cities and many churches. All of its inhabitants, except for a man named Trevilian, were killed in the flood as it swept across the land and pulled it under the sea. It is believed that only the mountainous peaks of Lyonesse now remain and could possibly be what is now known as the Isles of Scilly.

Human bones have been found in the sand around the area where Lyonesse is alledged to have been, fishermen have dragged up doors and window frames in their nets around this area and many sailors over the years have claimed to have heard church bells tolling from beneath the sea . Even a journalist in the 1930's claims to have heard the bells, but in modern times with men being able to dive and explore the sea nothing has yet been found.

It is true that there is a submerged forest in this area and fishermen have claimed to have seen the tops of ancient houses. Towers, spires and battlements have also been seen beneath the waves by a lady named Edith Oliver who claimed to have seen them as she stood on the cliffs of Lands End.