The most famous location in China was home to whole dynasties worth of imperial rulers.

The embalmed remains of the communist leader lie within a custom crystal coffin.

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.

Peace Park and the Atomic Bomb Dome.

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

Museum dedicated to the terror regimes of Hungary.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

An underground city of salt.

An institution dedicated to curiosity, logic, riddles, and Mongolia's long history of puzzles.

A huge communist-era propaganda monument and mural that offers stunning views of the Mongolian capital.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

The curious underground history of keeping Paris clean.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

Budapest's Communist-era statues, banished to the suburbs.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.