Venice's island of the dead.

A subterranean house of worship carved right out of the bedrock.

Single runway interrupted by a busy road that cuts across its middle.

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

Bridge that died in war and was resurected.

Mountain where Jesus was first tempted by the Devil.

World's largest bell sits on the grounds of the Kremlin in Moscow.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Regency-era excess on the English Coast.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

This one-time health resort was used by aristocrats around the world.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Pop culture has helped to keep this iconic British building from being destroyed.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

A whimsical bridge adorned with decorative dragons.

Museum dedicated to the terror regimes of Hungary.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Pompeii's less famous neighbor is still revealing her secrets.

100 year tradition of fist fights, marked by marble footsteps.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

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

Catacombs turned marketplace.