Pretty fascinating, that mosiac I'm guessing are descendants of the native (or that were here before the 'red' man) creating them. Mummies of 7-9 foot tall people have been found there along with duck decoys over 2000 years old. Those circles look like markers from something very high up, to align - and like many ancient cultures from all over the planet appeared to be communicating with something from above, ufo's -- who knows. it's fascinating. Here's some more info

https://www.oocities.org/age_of_giants/ancient_giants/sitecah.html