What a spectacular piece of architecture! I will definitely have to visit next time I am in India.
While it's fascinating to think about the amazing efforts that have gone into building this, I personally think that, rather than aliens, it is simply because humans were much more intelligent in the past than they are now.
As soon as we invented books, we had ways of storing our knowledge by writing it down, and therefore we could give our brains a rest. Now we have the internet, so we have even more access to information and knowledge. So we need to use our brains even less. I think it's natural that if we are using our brains less, then we will evolve (or de-evolve) to have less powerful brains in general.
The next stage of this development is when we actually become part machine; the birth of the age of cyborgs. This has already began and we will see great development in this in the coming decades.
Think about all of the islands in the South Pacific Ocean, that are thousands of kilometres away from the nearest continent; places like Fiji, Tonga, Tahiti etc. When the explorers of the 1500s, 1600s and 1700s were sailing the world and "discovered" these islands, they were already inhabited for thousands of years. If all people came from Africa originally, then how did these people get to these remote islands? They must have been highly intelligent and had amazing skills.
That's my theory anyway. Great post, looking forward to more from you!
Good explanation @donnymurph
Thanks a ton for reading this post :)