Places Jochen Duckeck Wants to Go

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

A mysterious crater-like pond has a spooky tendency to empty and fill with complete disregard to rainfall patterns.

A mountain cave is the site of archaeological findings and Paleolithic rock art.

Approximately 300 million years ago, a massive coral reef existed in what is now the largest limestone cave in Japan.

Grotto replete with mystical designs laid out in glued shell mosaics.

This Roman underground canal was the longest tunnel ever built until the late 19th-century.

See replicas of Europe's most famous cave paintings and even some of the animals that feature in the art.

A neighborhood park in the city of Cáceres hides what some believe are revolutionary examples of Neanderthal cave art.

The middle finger of modernity.

Following years of secrecy, the hidden history of a World War II site is being brought to light.

A labyrinthine underworld of tunnels and caverns hides beneath the city.

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

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

This enormous sinkhole hides a secret world created from divine wrath.

This 13th-century monastery chiseled into the side of a mountain is equipped with a bridge that can be lifted to protect against raids.

Underneath downtown Lincoln resides a network of caves that was also the city's first brewery.

This small but lovely sinkhole lake is the last remnant of a great prehistoric water basin.

In the bowels of a 19th-century brewery lurks a fine-dining restaurant offering an array of themed feasts.

Home to the longest wooden escalators in the world.

Chiseled out of a sandstone cliff, one farmer's unfinished art project lies in ruins.

A Turkish monastery tucked into a cliff wall.

An abandoned mine now resembles a post-apocalyptic landscape of derelict buildings and blood-red pools of water.

The grotto where Saint Ignatius of Loyola lived as a hermit for nearly a year.

A massive rock in the surf steeped in legends.