A preserved 18th century homestead in Western Pennsylvania marks the spot where the Whiskey Rebellion began.

One man's real life disfigurement inspired a lasting local legend surrounding an eerie tunnel.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

This secluded walking trail is a hidden gem of a Pittsburgh park.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

A six-ton wedding present for the King of the Scots.

World's largest bell sits on the grounds of the Kremlin in Moscow.

This newly renovated Soviet-era outdoor exhibition center is bigger than the principality of Monaco.

Former headquarters of the KGB.

A monument to Malchik, a stray dog who lived in a Moscow metro station until his tragic death.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Moscow's imposing monument to the Space Age.

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

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

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

Home to three historic ships from the age of Vikings.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

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

Turkish adventurer antiques in the heart of the Grand Bazaar.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

Inside this magnificent 12th-century church is one of the finest carved wagon-roofs in all of England.

A fountain standing as a testament to a doomed alliance.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

Ancient serpentine sacrifice holder that has stood the test of time.