Did Atlantis actually exist?

The myth or story of Atlantis is based upon a gigantic slip of land into the Atlantic or possibly Mediterranean, which contained a civilisation that was privy to lots of information that we no longer have. So yes, there is evidence of slip in the Iron Age in the Mediterranean and particularly around Turkey, but when it comes down to whether we've lost information which mankind would really benefit from today is a bit more difficult to demonstrate unfortunately.

As for the planets, people have interpreted it like that but most of the cave paintings are so bizarre that no-one really knows what they mean. They have animals, which is fair enough, and then they also have lots of demonic creatures. You then have people with duck's heads and so on. So the planet thing is one possibility but it's a rather slim one unfortunately.