Subterranean Sites

This massive subterranean fissure is known as the "underground Grand Canyon."

What was once an underground Nazi city is now Europe's largest bat reserve.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

Home to Hollywood history and a very special salt crystal.

These medieval tunnels provided water to the city above through centuries of civil war and plague.

One man's real life disfigurement inspired a lasting local legend surrounding an eerie tunnel.

Civil War dumping ground for the bodies of terrorized Union sympathizers.

This underground power plant looks more like a super-villian's lair than a public work.

An unfinished rail tunnel that has since been used to house cheese and bats.

The deepest metro station in the world.

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government.

Europe's second largest ossuary wasn't discovered until 2001.

Beneath the city of Lourdes, France is a massive, concrete church.

A watering hole where the options for seating include a bar, patio, or subterranean cave.

The cell which saved the life of Ludger Sylbaris, "the man who lived through Doomsday."

This volcanically volatile island town is home to an abandoned series of tunnels left by the Japanese during WWII.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.