Lyonesse is a kingdom which, according to legend, consisted of a long strand of land stretching from Land's End at the southwestern tip of Cornwall, England, to what is now the Isles of Scilly in the Celtic Sea portion of the Atlantic Ocean. It was considered lost after being swallowed by the ocean in a single night. The people of Lyonesse allegedly lived in what is described as fair towns, with over 140 churches, and worked in fertile, low-lying plains. Lyonesse's most significant attraction was a castle-like cathedral that was presumably built on top of what is now the Seven Stones Reef between Land's End and the Isles of Scilly, some west of Land's End and north-east of the Isles of Scilly. Lyonesse is mentioned in Arthurian legend, but particularly in the tragic love-and-loss story of Tristan and Iseult. Lyonesse is most notable as the home of the hero Tristan (one of the Knights of the Round Table), whose father Meliodas was king of Lyonesse. After the death of Meliodas, Tristan became the heir of Lyonesse, but he was never to take up his inheritance because Lyonesse sank beneath the sea while he was away at his uncle King Mark's court in Cornwall. In later traditions, Lyonesse is said to have sunk beneath the waves in a single night, yet stories differ whether this catastrophic event occurred on 11 November 1099, or 10 years earlier. According to legend, the people of Lyonesse allegedly had committed a crime so terrible that God took his revenge against them and their kingdom. The crime is never mentioned in any text or stories, but the legend tells of a horrific storm that occurred over the course of a single night, which resulted in an enormous wave that swallowed the kingdom and everything that was in its path. In what may have been a tsunami or tidal wave, the Kingdom of Lyonesse was lost forever and disappeared from the face of the earth as if it had never existed. The sole survivor Local Cornwall village tourism guides offer stories of a man who escaped the storm and a subsequent wave while riding a white horse. Apparently, the horse lost one of its shoes during the escape. The rider's name is thought to be Trevelyan (or Trevilian). The rider had been out hunting during the day and had fallen asleep under a tree. Trevelyan was awoken