This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

Richard Luke Concanen never set foot on American soil.

A rococo room covered entirely in porcelain originally constructed for another royal residence.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

The burial place of an obscure North African saint was turned into a macabre body preservation factory for the 17th-century Neapolitan elite.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

The sacristy of this church contains remains and relics of members of the Aragonese royal family.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

An unusual "skull with ears" sits in the crypt of this small church tucked away at the end of a narrow alley.

A celebration of all things tacky, garish, and bizarrely creative in the Romanian capital.

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

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

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

This snug medieval lane is one of the narrowest streets in the world.

A subterranean shelter remains intact under a busy Paris railway station.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

Burial mound for the ears and noses of thousands of mutilated Korean soldiers.

A beautiful bamboo trail tucked in this famous Japanese Shrine.