Archaeologists have Discovered an Underground Pyramid at Tiahuanaco in Bolivia

​The ancient fortress site of Tiahuanaco (Tiwanaku) in western Bolivia is still revealing secrets thousands of years after its peak as capital of an empire, and home to one of the most important civilizations prior to the Inca. 

Archaeologists from the Tiahuanaco Archeological Research Center have discovered an underground pyramid at the site using ground-penetrating radar.