Original pyramid found underneath two outer pyramids at Chichen Itza in Yucatan

A pyramid within a pyramid within a pyramid: That’s what archaeologists said they have found at the ancient Maya site of Chichén Itza in the Yucatàn Peninsula in the far south of Mexico.

Archaeologists have found a second substructure, possibly the oldest, underneath the two outermost pyramids at Chichén Itza’s El Castillo, a monument where researchers believe the people of the Yucatàn worshiped Kukulkan or Quetzalcoatl, the plumed serpent of ancient Mexico and Central America. The ancient people built the three pyramids in successive phases.

It’s possible this smallest structure, which one researcher compared to a Russian nesting doll or a matryoshka doll, was discovered previously, in the 1940s. But this year, scientists using an imaging process called tri-dimensional electric resistivity tomography, or ERT-3D, said they have found the much smaller pyramid underneath the two already-known pyramids. Though they have yet to excavate it, it may have a staircase to an altar at the top.

The visible structure (see photo above), known as El Castillo or the Castle, measures about 58 to 59 meters (190 to 195 feet) on each side. The next, intermediate pyramid below it measures 32 meters (105 feet) per side and 20 meters (65 feet) tall. The entire structure was built over a subterranean river or a cenote.

The enormous, 1,000-year-old temple of El Castillo is sitting precariously over a deep sinkhole and experts worry that the entire pyramid may eventually collapse, as Ancient Origins reported in 2015.