Once upon a Time, there was a continent in the Atlantic ocean, it was called Atlantis. There lived a human civilization far away from any civilization we know of today. The inhabitants of that land where called Merfolks, it is said that the city of future, Atlantis, and it's inhabitants, the Merfolk changed their appearance and became mermaids and merman, but legend has it that some of the Merfolks wanted to go back on land, where the continent was before it sunk. But no one ever heard of them again.
