A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

Italy's curious field of mud volcanoes is named for being both gross AND salty.

The "floating factory" was a highlight in the career of the Italian architect known for his unusual use of reinforced concrete.

Inside the small garden of two mid-century apartment buildings stands a centuries-old bell tower, separated from its original church and hidden from view.

An architectural oddity where the triglyphs of the courtyard of walls create an optical illusion.

Once the hunting reserve of a noble family, this is one of the few remnants of Pleistocene planitial forest in northern Italy that still stands.

A floating bridge leaning on barges allows pedestrians to reach the historical center.

Gutted during the Liverpool Blitz, this architectural husk has been left destroyed in honor of the dead.

19th century museum with an eclectic mix of curiosities, from Egyptian artifacts to items on archery history to the skull of the world's oldest horse.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

Have a seat with the father of modern computing at this Manchester monument.

A small monument in Lithuania marks the geographic center of Europe—or at least one of the claimants.

Ever-growing collection of devils in art.

A memorial to the murdered Jews of Kaunas.

A WWII museum that tries to reenact history.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

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

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Most prolific publishing house in the 1600s open to the public.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Brussels' favorite peeing boy has a sister.

A little sculpture with a large wardrobe.