Subterranean Sites

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

A surprising and unconventional mosque hidden in the subsoil of Istanbul.

Stockholm's deepest subway station is also a stunning ecological wonder.

A network of concealed passageways lies within a busy London Underground station.

This Roman quarry once held secret masses and smuggler's contraband and is now home to rare species of bats.

There's a labyrinth of manmade tunnels stretching for over an acre beneath Bristol.

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

The entrance to this sinisterly named tunnel hides behind a Tim Hortons.

The Netherlands' first car tunnel has an unusually rectangular shape.

World War II ended before these tunnels built to protect vital oil from Japanese bombs were ever used.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

A mysterious pillar in an ancient burial chamber is said to predict how long you have to live.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

A hidden tunnel leads to a medieval queen's shrine buried beneath a parking lot.

The romantic botanic tunnel feels like a well-kept secret.

This 1920s masterpiece of French Quarter architecture hides a secret tunnel used by Albert Einstein.

There's a labyrinth of medieval chambers hidden deep below a 15th-century pub.