The celebrated eyesore created by starry-eyed sweethearts.

The narrowest street in Paris.

Architect Le Corbusier built his friend a cubist house to match his impressive collection of cubist art.

Got apples?

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

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

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

France's most famous cemetery, with some of its most curious tombs.

This massive library holds what was once the largest book collection in the world.

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

A replica of the Liberty Bell rang daily from West Berlin's City Hall throughout the Cold War.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

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

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

A fascinating insight into daily life in the Eastern Bloc.

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

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

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.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

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