An underground nightclub helped spark a "Singing Revolution."

Celebrating the Swedish ship used in the first Arctic expedition to navigate through the Northeast Passage.

The palace for King Gustav III was never completed, but the foundation remains tucked away in this city park.

Few people have ever heard of, let alone visited, one of Turkmenistan’s most impressive natural attractions.

This cheerfully-named branch of the Chicago River is the fetid result of years of blood, entrails, and meatpacking waste.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

This park built on a former fortress has a reputation for romance.

The widest natural waterfall in Estonia is a sight to see in all seasons.

"There's nothing there," and other lies the KGB told us.

What started as a way to address damp basement walls turned into a house filled with intricate hand-carved designs.

A grumpy old water goblin guarding an old mill on the Devil’s Stream in Prague.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

This spooky statue sits outside a famous Prague theater.

What looks like a crashed Zeppelin is actually a bright, airy reading room perched atop a modern museum.

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

This artificial cave looks like something out of a fairytale.

Man-made mineral caves house massive bat colony.

Throughout this South Korean village, homes and businesses are covered in fantastic handpainted murals.

This former coal mine has been turned into a sprawling modern art complex.

Tracking the 1,500-year history of Korea's star cabbage.

The site of the last royal wedding in Korea.