By far, the most well known of Teotihuacán’s buildings is the massive Pyramid of the Sun. One of the largest such constructions in the Western Hemisphere, the pyramid’s curious alignment is believed to be based on calendrical cycles.
2. Easter Island
The enigmas surrounding the moai, Easter Island’s fleet of large stone figures, pretty much follow the same narrative as the other sites described here: How in the world did the Rapa Nui make these figures more than 1,000 years ago? And how did the moai end up on Easter Island?
Carved from stone, the nearly 900 human figures are sprinkled along the flanks of the island’s extinct volcanoes. The figures average 13 feet tall and weigh 14 tons and appear to have been chiseled from the soft volcanic tuff found in the Rano Raraku quarry. There, more than 400 statues are still in various states of construction, with some completed figures awaiting transportation to their intended resting place.
The reasons for carving the moai are mysterious, though they were likely sculpted for religious or ritual reasons. It’s also not exactly clear what happened to the stone-crafting Rapa Nui, but a leading theory suggests their civilization succumbed to an environmental disaster of their own making … which is something that probably could have been prevented had ancient aliens bestowed their infinite wisdom upon the culture.