New York City's only preserved family home from the 19th century.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

Mysterious 500-year-old tapestries depict a unicorn hunt.

Peek through the gates at this oasis from the city, full of Old English charm.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

On the top floor of an upscale department store stands a lavish restaurant housed in a replica of a luxury French dining car.

More gold than anywhere else, ever.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

The real life town from the Pied Piper of Hamelin has a mechanical puppet show that retells the famous story many times a day.

A kindergarten shaped like a cat with a tail that's a slide.

This 600-year-old home seems to defy physics.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

A collection of abandoned typographic signs from Berlin and beyond.

This century-old cinema house has a marquee that has been hand painted by a single man for over 25 years.

Skeletons dressed in extravagant 18th century royal costumes cavort in the aisles of this German basilica.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

A beautifully eclectic mix of architectural styles.

This classic restaurant features a gorgeous mirror-clad room.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

Island wonderland for communist autocrats.

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

This massive subterranean fissure is known as the "underground Grand Canyon."

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