Artworks by loners, prisoners and the criminally insane.

The World Wide Web was created in this nondescript corridor at CERN.

This small Milan street is filled with colorful homes and a rich history.

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

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

These hut foundations are believed to be the residence of Romulus, founder of Rome.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

This basilica is dedicated to two saints, one of which is known more for his famous quote.

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.

A Nesting Doll of Churches.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

An alchemist's "magic door" stands in the middle of a Roman park.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

Its interior is adorned with some of the best examples of early Christian mosaics.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

A dead saint, a deadly poison, and a mysterious holy ooze.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

This concept building is the UK's first attempt at making a permanent structure of nothing but trash.

Gladiators once walked this ancient, subterranean passage.

A sharp sculpture made of thousands of pieces of jagged glass.

According to legend, this ancient column contains healing properties.