So what was the point of adding aliens into all of this? They had their own religion and technology. It seems that other Indians just said that the place was built for the Gods. Sure it is impressive, but it's not extraterrestrial impressive.

The Mayans, for example, had observatories from which they viewed the constellations and could predict solar eclipses.

Lot's of societies managed this without extraterrestrial help. Why did they require it?