From Discovery News -

Hundreds of mysterious spheres lie beneath the Temple of the Feathered Serpent, an ancient six-level step pyramid just 30 miles from Mexico City.

The enigmatic spheres were found during an archaeological dig using a camera-equipped robot at one of the most important buildings in the pre-Hispanic city of Teotihuacan.

"They look like yellow spheres, but we do not know their meaning. It's an unprecedented discovery," said Jorge Zavala, an archaeologist at Mexico's National Anthropology and History Institute. read more