It was also built 3500 years later.

It's absolutely fascinating to me how this parallel development happened. There is no evidence of communication between the Americas Eurasia Africa at this time.

For context:

This was built right around the same time Europe started building Castles. Windsor Castle wouldn't be built for another 300 years though.

China was in the Song dynasty and was building really tall Pagodas around this time. They weren't quite ready for their biggest push on The Great Wall of China, that would come about 300 years later, though some sections were already 1500 years old at this point.