Places Jochen Duckeck Wants to Go

Some of the freshest vegetables in Seoul are grown in a subway station.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

A frozen oasis lies beneath the scorching New Mexico desert.

Was this cave created by Hercules's wrath, the devil, or volcanic activity?

These caves secretly held national treasures during World War II.

A winding cave grotto walkway built to provide employment for veterans after World War I.

A tangible and sobering reminder of an atrocity that took place during a secret war.

Bizarrely shaped rock formations in northwest Bulgaria come with equally bizarre legends.

Eat a Nobel banquet from any year in the basement of Stockholm's City Hall.

Thousands of well-dressed mummies below a monastery.

A network of underground water channels that dates back to the Middle Ages.

This tunnel was built in order to protect the village of Daroca from flash floods during rainy seasons.

This army of concretions is an unexplained geological phenomenon unlike anything else in the world.

A unique seaside cave where Aleister Crowley faked his own death.

A boat ride through utter darkness, lit only by headlamps, reveals an emerald green pool locals believe is sacred.

This Vietnamese hell cave lets visitors take a walk through a devilish underworld full of demons.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

The subterranean sanctuary home to local shamans is a sacred site for people of all religions.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

A massive underwater sinkhole made famous by Jacques Cousteau.

World's largest cave was only discovered in 1991, and now offers tours to the public.

A spiral staircase connects the limestone cave with Pembroke Castle, birthplace of King Henry VII.

A 15th-century former coaching inn forms the implausibly grand entrance to a 1980s shopping mall.

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