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

On Japan's Tashirojima Island, cats are king.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

Berlin's oldest surviving academic architecture hosted decades of animal dissections.

A slice of central Asia in the middle of Berlin.

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

A sweet museum focused on beets.

When German-Iraqi relations broke down, this embassy was vacated post haste.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Hamburgers are intensely proud of their tunnel beneath the river.

Model Trains and Much More in Hamburg.

A fascinating little museum dedicated to the thousands of chemical substances concealed in our food.

A preserved college lock-up that recalls a clubhouse approach to discipline.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

The only runway directly into the magic kingdom has been closed since 1972, but it still sings to you if you drive fast enough.

A book bound in the skin of an infamous criminal, along with countless other specimens.

The heads of two giant mythological water horses honor Scotland's horselord past.

A museum devoted to the science of color.

Collection dedicated to brands, packaging and advertising.

The world's oldest known salt mine.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.