A sculpture of a famous ape who was once a beloved household name in London.

Abstract dinosaur models in London.

The remains of Crystal Palace Great Exhibition of 1851.

This doorless 20th-century elevator doesn't stop or slow down.

A church of bones, decorated with 40,000 human skeletons.

France's national museum of scientific and industrial instruments.

Abandoned railway line circling the city of Paris.

This dazzling Art Nouveau mansion is now home to the Modern Art Gallery Subotica.

This one-time health resort was used by aristocrats around the world.

One of the best-preserved Roman amphitheaters is still used today, but for less brutal events.

The walls of this medieval church are covered with perfectly preserved frescos, including a pristine example of the Dance of Death.

A whimsical bridge adorned with decorative dragons.

This abandoned Slovenian military barracks has become a punky-political art squat.

The "dragon babies" of southeastern Europe.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

A miniature train-ride through Slovenia's largest cave system.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Inside the corridors of this flea market, visitors are sure to find some obscure and odd treasures.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

This cubist Vienna church building looks like some sort of alien stonehenge.

An exercise in radical design and social living that became the epicenter of Soviet spy networks in London.

A tongue-in-cheek arcade where the games are based on everyday life.

This mural painted by Keith Haring was done without payment as a gift to entertain the children at the Hôpital Necker.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.