The Yucatán Peninsula and Guatemala. The history of the Olmec and Maya have to be explained away by modern historians because it challenges the existing western historical view.
Discussion
I believe there are still some very interesting things about those civilizations that we haven't uncovered yet.
Without a doubt there were many civilizations before. To all of which there remains mysteries. All seemed to reach a peak of their civilization and technology and then had a sudden disappearance.
lydar flights over the jungles are revealing the massive number of man made structures that extend from the Yucatán, down through central America, and all over the Amazon, all the way to Peru.
It looks like at some point in the past, there was a diverse civilization of millions living all throughout the region.
The Mayan base 20 mathematics, with a representation for zero is also pretty crazy. Not quite as advanced as the Babylonian base 60, but close.
But the crazy thing is the calendar system with multiple interlocking circular time cycles which circle around each other and span the length of time it takes for our solar system to complete one rotation around the galaxy. Some advanced stuff.