Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

One man's exploration of the human form, including the bizarre and delightful "Man Attacked by Babies."

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

San Francisco's first World's Fair, dedicated to the wonders of California.

A hidden subterranean installation offers a view of the sky.

A famous alternative culture epicenter and where Joplin serenaded young hippies.

The oldest lawn bowling club in the United States.

An overlooked and unassuming engineering marvel.

A former ironworks that was the first UNESCO industrial site.

A socialist building dedicated to teachers showcases one of the largest Soviet mosaics in the world.

In the summer of 1957, a massive architectural exhibition showed off the future of urban living in this German neighborhood.

An astonishingly accurate water clock that doubles as an hourly spectacle in this Berlin shopping area.

Retirement home for giant obsolete machines.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

A quaint Russian village in the middle of a German metropolis.

It's always summer at the beach inside this former airship hangar.

The "Prussian Versailles" that is as glorious today as when it was built.

A helicopter memorial commemorating what was once the only way to access this West Berlin exclave.

Before he was forced to flee the country under Nazi rule, Albert Einstein spent his summers in this custom-built lakeside house near Berlin.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

Explore the complex ecology of this multifaceted nature preserve by riverboat.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.