This angular Dwarven tunnel cuts through a mountainside in Glacier National Park.

This off-the-beaten-path abandoned town is a relic of Montana's silver mining boom.

This amazingly preserved Gold Rush town is a historian's dream.

One home in the historic strip hides secret compartments and the ghostly songs of long-gone canaries.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Collection dedicated to funeral rites, equipment, and mourning rituals of the Viennese.

One of the best collections of wax anatomical models in the world.

This museum promotes informed contraception by documenting its often secret past.

Macabre museum devoted to historical Viennese murders.

The final resting place for the remains of 143 Habsburg royalty.

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

Museum dedicated to wax representations of disfiguring diseases.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

An existential riddle in the world's largest ancient castle.

Microscopic scenes; some call it novelty, some call it art.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

This doorless 20th-century elevator doesn't stop or slow down.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

A series of playful yellow penguins share a serious message about the environment.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

One of the world's largest collections of pharmaceutical artifacts.

Most prolific publishing house in the 1600s open to the public.

Quito's historic, main square dates back to the 16th century.