Rome's semi-secret peephole vista is also a former Crusader stronghold.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

A mechanized clock where a man fights off a dragon, crab, and rooster.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

A museum of carnival attractions where you are invited to ride the rides.

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

A scrap-metal sculpture recalls an infamous 19th-century camel.

The shop's owner has spent decades in the desert wearing nothing but a strategically placed sock.

Ever hear of the Milazzo Cage?

An 18th century fountain and two columns are all that remains of Rome's forgotten river harbor.

A statue representing a lost Roman profession that was vandalized for centuries.

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

The former home of an Italian artist is now a shrine to his ambitious works.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

One of seven Jewish catacombs in Rome and one of only two open to the public.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

A hospital where antique dolls are given new life.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

A Bronze age settlement on the Greek island of Santorini might have been the inspiration for Plato's Atlantis.

This graffitied 19th-century building was a prototype of European industrial architecture.