The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

A public urinal so pretty, it was declared a national monument.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

The art critic claiming that "only an ape could have done this" was in fact right.

The lost American era of gunfighters, bandits, Indians and steam trains is recreated in Sweden.

The trailblazing Swedish businesswoman created a beloved minty candy called polkagris.

A forest of immensely tall and unusually straight oak trees planted nearly 200 years ago to build naval ships that never came to be.

A replica of the beloved character's house, modeled after the author's own drawings.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

This hidden collection of everyday objects illustrates life within communist Poland.

A heated statue pays tribute to one of Sweden's great actresses.

A golden plaque marks the site of the mysterious unsolved assassination of the former Swedish prime minister.

A former suicide bridge is now accumulating symbols of love instead of a body count.

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

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

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Stockholm's deepest subway station is also a stunning ecological wonder.

The library's graceful rotunda is like a bibliophile's temple.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.