Breathtaking Byzantine paintings cover the inside of this 12th-century church.

The ancient mosaics here are considered among the finest in the world, and serve as a stunning record of Greco-Roman daily life.

A magical museum of fairy tale treasures near Cyprus' buffer zone.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

A hidden workshop for creating and restoring Papal mosaic masterpieces.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

A museum of magic with a Sadist past.

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

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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

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

This massive library holds what was once the largest book collection in the world.

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

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

A museum and shop on Bourbon Street located in the French Quarter.