This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

Elevated freight railway turned wildly successful urban park.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

These fantastically named natural pools look like something out of a Scottish myth.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

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

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

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

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

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.