Part bookstore, part café, and part forest.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

Cathedral carved out of salt, located a mile below the earth's surface.

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

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

Frida Kahlo's childhood home, now a museum of her life and works.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

Old Danish castle immortalized in Shakespeare's Hamlet.

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Perfectly preserved ancient monastery in an impossibly dramatic location on a rocky island in the Atlantic.

An Irish town has built a statue to a silent film actor simply thanks to the holidays he once spent there.

Where commuters walk through remnants of an ancient Greek necropolis.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Giant topiary dog once played a role in a terrorist bomb plot.

Elevated freight railway turned wildly successful urban park.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A monument celebrating the idea of reaching inaccessible places.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A historic presidential getaway on the continental United States' southernmost island.

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

The United States Capitol's former columns still stand.

Commonly acknowledged as the only public monument to the Devil himself.