The art museum is decorated with creatively remodeled pre-Nazi swastikas.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Copenhagen's celebrated theme park and gardens.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

This one-time health resort was used by aristocrats around the world.

A miniature train-ride through Slovenia's largest cave system.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A pair of connected skyscrapers form this symbolic gateway.

Oriental bazaar in the heart of Sarajevo.

This subterranean disco dance club in a Cuban cave comes with bright lights and a dark legend.

Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.

A colorful narrow alley in Cuba is full of street art and sculptures made of found objects.

A focal point of the Cuban government, this city square features one of the most iconic images in the country.

This imposing memorial contains the remains of Che Guevara — and 29 other guerrillas who died with him in Bolivia.

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.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

Apartment complexes built into huge repurposed natural gas tanks.

This museum promotes informed contraception by documenting its often secret past.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Dine amidst exotic plants at this former royal greenhouse.