Diego Rivera's massive tiled fountain and failed infrastructure project.

66,000 pieces of art, donated by one of the world's richest men.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.

Part bookstore, part café, and part forest.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.