Races of men and real world counterparts?

[Daisy Brambleburr]

When I was reading a book on Mythology I saw that, according to myth, there was once an island called Lyonnesse that was somewhere off the coast of Cornwall.

once a region West of Cornwall, now sunk beneath the sea more than 40 fathoms deep. The Lyonnesse of Celtic legend, the home of Tristram and of the Lady of Lyones, has been identified with Lothian in Scotland.

The great Arthurian epics of medieval Romance turned the lost land of Cornish folklore into the legendary kingdom of Lyonnesse. The prince of this lost land and noble race was Tristan - the most accomplished of Arthur's champions and the famed lover of Isolde. It was to 'the sunset bound of Lyonnesse ... where fragments of forgotten peoples dwelt, and the long mountains ended in a coast of ever-shifting sand' that Arthur 'ever pushed Mordred, league by league' as he pursued him across Cornwall, according to Tennyson's Idylls of the King. The Scillies are the high peaks of ancient Lyonnesse, so legend tells - two of its islands are known as Great and Little Arthur. Accordingly, from the westmost point of Lyonnesse, now the Scillies, Arthur lured Mordred's entire army towards him. This version of the flood story relates that Merlin then caused a great earthquake to send a tidal wave to drown Mordred's army and so flood Tristan's land of Lyonnesse.

I'm not sure if Lyonnesse and Atlantis are thought to be the same place, but it does sound a little like Numenor. What do you think?