Be on the lookout for the symbolic insect all over the city.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

Modern megaliths form this work of cosmic, Celtic landscape art.

A historic cave in Scotland once served as a hiding place for a famous Covenanter.

Forgotten jail cells beneath this Scottish town hall are now used for delightfully artful storage.

This observatory within Europe's first dark sky park offers stunning views of the night sky.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This Parisian café sticks almost exclusively to an ethos of reuse.

The oldest stone house in Paris was built by its most famous alchemist.

France's most famous cemetery, with some of its most curious tombs.

Notorious artist squat renovated into legal studios.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The gravestone of a delicate singer-songwriter bears a fittingly introspective epitaph.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

The longest hedge maze in the world.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.