Nesting Doll Pyramid: Ancient Mayan Structure Found Inside Chichen Itza

What do a Russian nesting doll and a Mayan pyramid have in common? Archaeologists have confirmed that the iconic Pyramid of El Castillo in eastern Mexico is actually a pyramid within a pyramid within a pyramid. In the 1930s, the first hidden pyramid was revealed within the Kukulkan tomb at Chichén Itzá in Mexico, which researchers estimate was built between about A.D. 850 and A.D. 900.