A 12th-century fortress containing some of Berlin's oldest buildings.

This Berlin island is home to a flock of free-roaming peacocks, as well as a historic ivory folly.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

A collection of abandoned typographic signs from Berlin and beyond.

A wunderkammer of mysterious objects and stories.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A surreal museum of extraordinary industrial objects.

A slice of central Asia in the middle of Berlin.

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

Started as a kitchen garden, now the second largest botanical garden in the world.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

An eerie, derelict amusement park in Berlin.

A European-style bath house in Chicago.

In one Chicago park, a trio of werewolves are waiting to devour their fallen brethren.

A display of magnificent stained glass windows is the first exhibit of its kind.

A century-old network of freight tunnels underneath the city's historic business district.

In Chicago, a pizza-enthusiast has opened a museum dedicated to the history of pizza.

Designed by Alfred Caldwel, this landscape showcases his vision of a native garden.

A Museum of Holography frozen in 1974.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

Over 1,000 pieces of one of the most niche art objects imaginable: the glass paperweight.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.