Underwater art project will double as a massive artificial coral reef to help regenerate the damaged ecosystem.

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

An Aztec snake god has taken the material form of an apartment complex.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

These azure waters were thought to lead to the Mayan Underworld.

One of the city’s oldest watering holes was originally the home of a famous James Brown (not that one).

These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.

The largest arcade museum in the world chronicles the golden age of video games which ended promptly in 1987.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

Where monkeys run wild and the humans are caged.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

Wading through a small lagoon reveals a secret, wild stretch of pristine beach.

A hidden beach at the end of a tunnel of mangrove trees.

The often-overlooked ruins of one of the first buildings designed by famous landscape architect Frederick Olmsted.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

The first American department store, and home to the largest operating musical instrument in the world.

Huge masonic hall in Philadelphia with lavishly themed rooms.

The abandoned coal loading dock is a canvas for unsanctioned art.

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

The oldest surviving botanic garden in the United States.

One artist's love letter to his city and its citizens plays out across dozens of bright murals painted on the sides of decrepit buildings.

A layered tribute to the work of mosaicist Isaiah Zagar.