Places KLM602 Wants to Go

This vast and otherworldly landscape is one of the largest dune complexes in North America.

Dine amidst exotic plants at this former royal greenhouse.

Visiting this café is like visiting the Austrian grandma you wish you had.

Macabre museum devoted to historical Viennese murders.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

Abandoned railway line circling the city of Paris.

This massive library holds what was once the largest book collection in the world.

France's most famous cemetery, with some of its most curious tombs.

This bizarrely tree-like red skyscraper is one of the newer additions to Barcelona’s skyline.

Dunk your churros in rich hot chocolate on the city’s old “Chocolate Street.”

The unexpectedly beloved remnants of a controversial thermal power plant.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

Mountain where Jesus was first tempted by the Devil.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

A beautiful but toxic fountain of mercury.

Dress up like a miner and take a slide into the disco-lit depths of this once foundational salt mine.

A subterranean display of public art and architecture.

Hamburgers are intensely proud of their tunnel beneath the river.

This unique Renaissance castle was turned into a home for Nazi occultism.

Slaughterhouse Five opens its dank doors to fans of Kurt Vonnegut.

What was once thought to be a wellspring of unicorn bones is actually just a prehistoric burial site.