The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

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

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

Discover the past, present, and future of packaging in this unique Japanese museum.

A King Kong-like gorilla hangs from the top of this commercial building in Tokyo.

Every color in the rainbow awaits.

Tokyo’s only Vaudeville-cuckoo clock–steampunk-Victorian curio cabinet time piece.

Transport yourself to the 1980s era of video games at this themed restaurant and bar.

Where sweethearts leave their love locks in the Uruguayan capital.

The oldest café in Montevideo preserves its history as the city's bohemian hub.

A gateway to a mysterious network of underground tunnels.

Buenos Aires' city of the dead contains some very famous remains, including Eva Perón.

"Di amigo y entra" at this Argentinian Middle Earth-inspired pub.

This plaza at the end of the world teems with monumental tributes to a problematic history, and laser discs.

Xul Solar was an artist of alternate worlds, inventor of languages, and dreamer of utopias.

This egg-shaped treehouse was inspired by "sport sleeping."

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

This museum is housed in an unassuming building that witnessed one of the most daring feats of satire in modern history.

An abandoned water park overtaken by the dunes.

This African beach is home to thousands of rare mainland penguins that are known for their annoying voice.

Formerly known as the Malay Quarter, Bo Kaap is a colorfully-painted suburb located in the “Mother City” of South Africa.