Once upon a time these giant concrete tanks were used by local fishermen to clean their wild-caught mussels.

This sculpture marks the spot where one of the greatest Roman rulers was proclaimed emperor.

A century-old tradition has culminated in a small but singular collection of feline effigies.

Follow the original medieval paths that wind through this intriguing section of the city.

This popular square's history as the former site of a church is right beneath your feet.

One of the shortest streets in York has an especially odd name.

This centuries-old pub boasts a collection of more than 4,500 snippets of neckties from around the world.

This battery powered bell has been ringing since 1840 and is one of the worlds longest running science experiments.

The beautiful non-repeating pattern honors the Oxford professor who discovered it.

This Norman castle was once the site of a Victorian-era prison, and now exists as a luxury hotel.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

The beloved fantasy novelist is buried near a church containing a whimsical etched glass window full of Narnia favorites.

The spot where three Protestant clergymen were burned at the stake during the reign of "Bloody Mary."

Hidden in plain sight, this creepy sculpture watches from above.

The remnants of this unusual bridge await an uncertain fate.

A letterbox installed specifically for the first editor of the Oxford English Dictionary.

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

An abandoned NSA listening post on Berlin's "Devil's Mountain."

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.

Known simply as "The Hand," this famous public sculpture in Berlin was featured in a Depeche Mode music video.

A wunderkammer of mysterious objects and stories.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

A unique Holocaust memorial tells the personal stories of the Jewish residents exiled from greater Berlin.

This platform is now a memorial dedicated to those who were deported during the Holocaust.