A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A slice of central Asia in the middle of Berlin.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

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

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Hidden just under the waters around this Turkish island are the ruins of a once great city.

A marvel of Byzantine engineering under the streets of Istanbul.

A secret climbing tree hides along the side of a Costa Rican road.

A fantastic place to see murals, and an important location in the history of Toronto's legal street art scene.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A book collector's dream, this Toronto bookstore has the world's first "Biblio-Mat," a random book vending machine.

An ancient knight and a symbol of the city's freedom.

An ethereal glowing blue ocean cave in Croatia.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

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

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

Inside this mansion turned museum, the works of prominent Croatian artists are on full display.

Where the lovelorn find a home for their sentimental keepsakes.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.

These tiny effigies are believed to represent victims of Edinburgh’s notorious Anatomy Murders.

The fountain marks the area where hundreds of accused witches were burned at the stake.

A book bound in the skin of an infamous criminal, along with countless other specimens.