There are 220 items filed under subterranean sites.

Budapest, Hungary

Hospital in the Rock

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest
12 Feb 2014
Ternopil's'ka Oblast, Ukraine

Priest's Grotto

A subterranean Holocaust refuge within one of the world's longest cave systems
04 Feb 2014
Slaughter Beach , Delaware

Redbird Reef

Decommissioned NYC subway cars are dumped into the ocean to create this underwater wildlife habitat
28 Jan 2014
Landrethun-le-Nord, France

Forteresse de Mimoyecques

Underneath a chalk hill in France lies what Hitler hoped would be the underground launching base for a devastating new weapon
20 Dec 2013
Bonne Terre, Missouri

Bonne Terre Mines

The world's largest man-made underground caverns offer unparalleled underwater wonders
16 Dec 2013
East Granby, Connecticut

Old Newgate Prison

A former copper mine which became a truly unsuccessful prison
21 Nov 2013
Derbyshire, United Kingdom

Blue John Cavern

A semi-precious cavern system that not only mines rare minerals but also tourists' dollars
15 Nov 2013
Montreal, Canada

Beaudry Metro

Montreal's colorful subway station showing its support of the local LGTB community
01 Nov 2013
Beijing, China

Dixia Cheng - Beijing's Underground City

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination
01 Nov 2013
Clay, Kansas

The Kansas Underground Salt Museum

Home to Hollywood history and a very special salt crystal
18 Oct 2013
Marble Falls, Texas

Dead Man's Hole

Civil War dumping ground for the bodies of terrorized Union sympathizers
07 Oct 2013
Division No. 10, Subd. D, Canada

Churchill Falls Generating Station

This underground power plant looks more like a super-villian's lair than a public work
26 Sep 2013
Walhalla, South Carolina

Stumphouse Tunnel

An unfinished rail tunnel that has since been used to house cheese and bats
25 Sep 2013
Kiev, Ukraine

Arsenalna Metro Station

The deepest metro station in the world
23 Sep 2013
Allenwood, Pennsylvania

Bunkers of Alvira

Over 100 concrete munitions bunkers are all that remain of a Pennsylvanian village seized by the US government
20 Sep 2013
Brno, Czech Republic

Brno Ossuary

Europe's second largest ossuary discovered in 2001, nearly ready to be opened
30 Aug 2013
Lourdes, France

Basilica of St. Pius X

Beneath the city of Lourdes, France is a massive, concrete church
28 Aug 2013
Nevada City, California

Old Stonehouse Brewery

A watering hole where the options for seating include a bar, patio, or subterranean cave
21 Aug 2013
Saint-Pierre, Martinique

The Prison Cell of Ludger Sylbaris

The cell which saved the life of Ludger Sylbaris, "the man who lived through Doomsday"
13 Aug 2013
Blegny, Belgium


Descend into the tunnels to experience the life of a coal miner
25 Jul 2013
Greater Sudbury, Canada

Sudbury Neutrino Observatory

A neutrino detector built into the largest man-made underground cavity in the world
12 Jul 2013
London, England

Greenwich Foot Tunnel

A 1,215-foot tunnel transports pedestrians beneath the River Thames
09 Jul 2013
Udabno, Georgia

Davit Gareja Cave Monastery

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside
08 Jul 2013
Lakonia, Greece

Cape Matapan Caves

A cave network located at the southernmost tip of mainland Greece was once believed to be an entrance to Hades
03 Jul 2013
Vilnius, Lithuania

Kaunas Museum for the Blind

Museum deep in the catacombs of St. Michael the Archangel Church is explored by touch, sound, and smell
28 Jun 2013
Marshall Islands

Cactus Dome

An enormous concrete structure built over a nuclear crater
28 Jun 2013

The Crystal Maiden of the Actun Tunichil Muknal Cave

Belize cave containing the sparkling, calcite covered skeletons of Mayan children, sacrificed to the rain god
26 Jun 2013
Portland, Oregon

Portland's Shanghai Tunnels

The seamy, underground secrets of Portland's criminal past
21 Jun 2013
Istanbul, Turkey

Basilica Cisterns of Istanbul

A marvel of Byzantine engineering under the streets of Istanbul
20 Jun 2013
Aubeterre-sur-Dronne, France

Underground Church of Saint-Jean at Aubeterre-sur-Dronne

The largest underground church in Europe
20 Jun 2013