This monumental work of art symbolizes the coming together of a previously divided city.

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

The celebrated eyesore created by starry-eyed sweethearts.

During the summer months, giant teddy bears take over Paris near Les Gobelins metro station.

The video game-themed street art first popped up in the French city.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Paris' linguistic guide to the international language of, yes, love.

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

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

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

This nightmarish children's plaything was left grotesque to help kids conquer their fear.

A museum dedicated to the history and exploration of both popular music and science fiction.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Where a Japanese government official issued transit visas to Jews fleeing from Nazi-occupied Poland.

Elevated freight railway turned wildly successful urban park.

A memorial to the murdered Jews of Kaunas.

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

Tel Aviv's popular neighborhood went though endless waves of transformation.

This clock is an architectural flourish that stands out as a landmark among a unique Israeli German community.