unlimited mind,
I got some intuitive help from someone who has an Atlantis connection because I thought it might be part of Atlantis and here is her response:
"I did a quick meditative look at it and the only thing that pops up is that it was done not by indigenous people, but by beings/people from an off planet culture. If this is the case, it could be that the place is energetically significant in some way. Let me know what you get on this if you have a chance."
That would be such a great find unlimited if this is the case. But how do you prove it? That is the hard part.