Places Jochen Duckeck Wants to Go

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

This subterranean passage reveals the city's mining history as well as its legendary terrors.

A mysterious set of tunnels carved in the hills of rural northern Kyushu.

An Ancestral Puebloan ruin that appears to burst into flames in the sunlight.

An eerie former warehouse turned cistern turned movie set.

A sixth-century Byzantine cistern hidden below a modern carpet store.

The largest wine cellar in the world is a 150-mile network of underground caves near the capital of Moldova.

A subterranean relic of the Spanish Civil War hides below this picturesque park.

The stunningly blue waters of these beautiful caves also have a violent past.

This ancient subterranean megalopolis is known for the hot oil traps that were installed above each of its entrances.

No one knows who built this strange cave of worship or exactly why.

A soon-to-be-forgotten roadside spectacle loaded with local lore.

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

This region of Slovakia boasts some of the most plentiful opal mines in the world.

A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

This hidden art nouveau gem was designed by an architect in search of a national style.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Once the home of a hermetic monk, this cave now houses a small church.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

This mesmerizing medieval monastery-cave complex sits thousands of feet above ground overlooking a valley.

Seventy-five miles of limestone caves host more than a million bottles of wine beneath a sleepy Moldovan town.

Some locals believe the fabled lost gold of General Yamashida is hiding somewhere beneath the city.

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.