Widely advertised as Amsterdam’s narrowest street, this passage was once a highlight of the Red Light District before its windows closed.

Europe's official "zero-level," the equator of elevation.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

This 135-year-old weather station studied the effects of the climate on human health.

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

A miniature train-ride through Slovenia's largest cave system.

A remote crossroads honoring a fallen talent.

A trading post in the North Pole where children send letters.

A museum dedicated to restoring vintage aircraft, located at a working airport.

A non-native grove of 241 redwoods in Southern California.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

Romania's triumphal arch looks out over Bucharest.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This once-derelict building is now one of the most beautiful bookstores in the world.

This hobbit-y little hot spring may be the oldest spring used by humans in all of Iceland.

A giant desert bird that once swung music fans at Coachella now has a home in a nearby traffic circle.

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

Tiny memorials honor individual victims of the Holocaust.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.