Vast network of air raid tunnels beneath Lombardy's capital.

This curious building hides eclectic details like medieval gargoyles alongside naked angels and Art Nouveau mosaics.

Just across from the "Last Supper" painting is the famous painter's vineyard, a gift received for creating the masterpiece.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

A Milanese café entirely designed by the American director Wes Anderson.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

A Parisian boutique devoted to la Sape, the elegant Congolese fashion subculture rooted in European colonization.

An unusual number plate signifies the building's saucy past.

Ordinary art transforms to extraordinary thanks to locals' quirky sense of humor.

This innocuous-seeming building is actually the remnant of a major wartime brothel.

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

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

19th century pendulum and a clock restored by a rogue group of guerilla artists.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

This frog-themed restaurant was frequented by Picasso, Saint-Exupéry, and more.

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

Abandoned railway line circling the city of Paris.

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

Walk through a restaurant's refrigerator door to reach this hidden bar.

A plain wooden seat that once belonged to one of the most prominent figures of the Protestant Reformation.

The world's largest second-hand graces a clock surrounded by constantly changing flower beds.