This contentious squat has stood through fire, violence, and government intervention as a hotbed of leftist protest.

This bar and museum are devoted to the controversial comic book work of Kája Saudek.

Super-heavy Nazi architectural experiment.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

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

This 13th century Gothic brick castle is the largest in the world by surface area.

Stockholm's narrowest alley is barely over two feet wide.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

This red light district plaza memorializes the Fab Four and their historic connection to the area.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

This artistic fountain display pays homage to this area's theatrical history.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.

One of the world's largest collections of pharmaceutical artifacts.

One of the world's few mounted blue whales, its jaws are hinged open allowing visitors to descend into a lounge.

This tree was grafted from the actual tree that led Isaac Newton to ponder the theory of gravity.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

This feat of Brutalist architecture is also known as the Three Sisters.

This former KGB building is now a museum memorializing the people who suffered during the Soviet regime.

Plaques celebrating Lithuanian writers freckle a wall of this picture-perfect path.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

This micro-nation may be some sort of prank, but its constitution sure seems official.

This fascinating museum in an old water tower holds the world's largest collection of Vodou artifacts from western and central Africa.