The religious shrine that Pablo Escobar's men would allegedly visit before completing a mission.

A Buddhist shrine in a cave protected by macaques next to dark passages lined with creepy paintings.

The first artificial white water river course in North America cuts right through an Indiana city.

One-layer pyramid in Indiana.

This open air cathedral invites all faiths to worship under the only roof big enough to fit them all: the sky.

Modeled after the labyrinth in Chartres Cathedral, this small-town Indiana memorial labyrinth sits half a world away.

A lesser-known part of the Kinsey Institute is this impressive collection of art, artifacts, and material culture related to human sexuality.

This elaborate estate contains a stunning marble aviary, a sunken conservatory, and a magnificent music room with a two-story pipe organ.

Locals dubbed this abandoned abode the "gingerbread house" because of its odd architecture.

A turn-of-the-century architectural marvel built on healing mineral springs and salt licks.

The longest navigable underground river in the United States is home to countless blind and albino animals.

An abandoned Jazz Age dream home and con man's hideout in Death Valley.

An eccentric German artist built this weird and wondrous castle packed with shocking sculptures and alien art.