Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

A memorial commemorating the place where Truman gave the order to deploy the first nuclear bombs on Japan.

A quaint Russian village in the middle of a German metropolis.

The final resting place of the author who gave us the Little Mermaid, the Ugly Duckling, and many more beloved fairy tales.

The world's first combination ski slope and power plant.

A novel collection of medical curiosities housed in an 18th-century surgeon training academy.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

Hans Christian Andersen for the postmodern world.

This sublime architectural marvel is a rare example of an expressionist church.

A tiny slice shop hides down an unmarked hallway in a Las Vegas casino.

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

A piece of the iconic wall found an unlikely new home in a Vegas bathroom.

This enormous Hindu temple in Queens serves incredible dosas in its basement canteen.

The first and only carousel with a lineup entirely of insects.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

Love, knishes, and best wishes from this legendary Lower East Side bakery.

A celebration of capitalism in Midtown.

New York City's smallest piece of private property.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

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

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A crumbling hospital from the 1850s on Roosevelt Island.

A museum dedicated Germany's favorite drink and most well-known festival.

A wunderkammer of exoticism immortalized by Tom Waits.