A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

A semi-scholarly approach to sex.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Elevated freight railway turned wildly successful urban park.

A crumbling hospital from the 1850s on Roosevelt Island.

A terrific purveyor of natural history objects and curios.

Superstitious? Discover the witchy side of Mexico through its largest esoteric market.

Traditional 11th-century outdoor tannery.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

The other side is actually green.

A massive sea stack famous for its appearance in The Goonies.

100-year-old shipwreck you can walk up to at low tide.

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

An emporium for the weird, creepy, rare, and just plain gross.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

The large collection of pre-Columbian pottery might make you blush.

These ruined Incan mausoleum towers still bear carvings of sacred animals on their blocks.

A kitschy Italian medieval-style castle incongruously located amidst one of the most historic towns in the Peruvian Amazon.

This stone complex marks the urban center of a lost civilization.

The remains of what was the most important religious complex in coastal Peru for over a millennium.

The mysterious "Candelabra of the Andes" could represent anything from a god's trident to a hallucinogenic plant.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

An unexpected desert oasis in South America.

A market for witches is hidden within a train station.