"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

The "Mystery and Company of Merchant Adventurers" is an Elizabethan-era hangout in Moscow.

Inside the world's largest seed bank, WWII botanists elected to starve to death rather than compromise their collection.

A collection of collections ranging from dentistry to minerals.

Stockholm's deepest subway station is also a stunning ecological wonder.

This statue and park honor the Swedish chemist Jacob Berzelius, one of the founders of modern chemistry.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Sweden's oldest animated sign is still lighting up the skyline today.

This legendary dessert was served to Nobel laureates for decades.

A deserted hodgepodge of experimental structures designed by nearby university students.

One of the largest cat sanctuaries in North America is considered a "Club Med" for felines.

South Korea's love of the silly photograph is on full display at this goofy collection of trompe l'oeil paintings.

A forest park outside Tallinn full of architectural and artistic curiosities.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

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

Home to items never before seen by the public.

Norway has built what may be the world's most beautiful public toilet.

A quaint museum nestled in a former hub of Irish moss harvesting.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.