A black cat protests the City Guild in Riga's Old Town.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

A museum in the building where Nazi Germany signed its surrender tells the story of World War II from the Soviet perspective.

Visitors can explore the role of mysticism throughout the ages inside this interactive museum of magic.

A portable, wooden replica (minus the hyphen) of Hamburg’s iconic crooked coffee shop.

Cold war icon and onetime "hole" in the iron curtain.

One of downtown Berlin's last reminders of its Communist past.

Berlin's oldest surviving academic architecture hosted decades of animal dissections.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

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.

A fascinating insight into daily life in the Eastern Bloc.

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

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

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

A gleaming white and undulating tower marks the border between Georgia and Turkey.

A 12th-century church with a medieval fresco and an intriguing “Greek runestone.”

The scars of a remarkably organized public protest to save 13 elm trees are still visible in this Stockholm park.

Early habitat dioramas and home of the elusive gaff, the skvader.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.