cabeza colossal

aka Big Head.

Olmec. These guys were kicking around before the Maya came to town.

Can't really tell from the pic, but this guy's head is about 9 feet high.

Museo Nacional de Antropología
Mexico City, MX

under our feet

Ninety-five percent of Mexico remains essentially unexplored.

David Grove, a professor emeritus of anthropology at the University of Illinois at Urbana-Champaign, who has worked in central Mexico for more than 40 years, as reported by National Geographic in Ancient City Found in Mexico; Shows Olmec Influence

And that which has been found is being eaten by acid rain.