There are many myths about cities lost beneath the oceans of the world. Perhaps the best known of these is Atlantis. In Celtic legend a lost land such as this is called Tir na-Og, 'the Land of the Young'. It is told that every seven years Manannan MacLir, the god of the sea, gave permission for the underwater world to show itself above the waves. Its towers and rainbow coloured flags inticed many sailors towards it, there on the horizon.

Legend tells that if by enchantment you reach the magic land you will never be able to return to this world.