This seaside Italian village doesn't just look Escher-esque, it actually inspired the mind-bending artist.

A narrow opening between the mountains of the Amalfi Coast creates a scenic hidden beach.

A crumbling watchtower and a lighthouse overlooks the site believed to be the Sirens' cliff in the "Odyssey."

The enchanting home of an eccentric Swedish physicist and author sits in the hills of Anacapri.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

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

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

An ancient Roman temple first dedicated to an emperor's wife is now a church.

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

A rather vulgar example of the transition from Latin to the Italian vernacular.

A Nesting Doll of Churches.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

Rome’s legendary peephole vista is also a former Crusader stronghold.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

Secret refuge and museum of the Duke of Florence.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Venice's "Island of the Mad."

Two stone columns flank the grand Venice square, but there were supposed to be three.

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

Where Venice's gondolas go for a tune-up.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

The world's longest and deepest train tunnel.