The source of America's longest river is also a historical landmark and the start of a famous nude run.

A luxurious doomsday bunker hidden beneath an unassuming Las Vegas home offers the best of subterranean suburbia.

At just 51 feet and 10 inches long, it's the shortest street in England.

Decrepit Victorian public lift is a white-knuckle ride.

A private selection of curiosities, carefully curated by a young Brighton local.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

An eerie collection of the surviving structures from a past celebration of the future.

The final resting place of the great navigator, or maybe his brother.

Before this bridge was built people had to wait for the ferryman, an annoyance that, the story has it, gave the town its name.

This French chateau is home to the world’s largest private collection of fighter jets.

Only the facade of this house was built so a father could fool his son.

This bridge's unique architecture honors nautical heritage and encourages self-awareness.

The only surviving piece of Copenhagen's 16th-century defensive wall.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

Hotel designed by indie graphics artists.

An ancient tree that was once the favorite of a young Swedish royal.

Stockholm's last remaining paternoster elevator.

A former suicide bridge is now accumulating symbols of love instead of a body count.

Created as a punny statement about genetic engineering this monstrous hybrid statue has become a beloved icon.

Gutted during the Liverpool Blitz, this architectural husk has been left destroyed in honor of the dead.

The red letters in the literary pavement leading to the library form a mysterious code.

This aging storage facility is the world's largest brick warehouse.

Modern commuters still pass through this 2,000-year-old Roman archway.