Jumping-off point for a climb up Mt. Everest is the most dangerous airport in the world.

Last stop before the top of the highest peak in the world.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Puppet theater and museum holding a collection of more than 300.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

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

Macabre astrological automaton clock dating to the late 1400s.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Shop of curiosities with a dinosaur museum tucked in its basement.