This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

This former papal residence was the site of an infamous incident known as the “slap of Anagni.”

This Roman theater was crafted into the local tuff rock and was rediscovered during the 19th-century.

This splendid mosaic embodies ancient Rome's fascination with the exotic allure of Egypt.

This is the oldest Roman-made bridge in the city still existing in its original state.

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

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

The “Sistine Chapel” of the Middle Ages merges 11th-century science and religion in wondrous hues.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Fortified medieval tower house with lovely roof garden.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

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

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Architectural monsters are devouring this palace's every door and window.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

Thousands of well-dressed mummies below a monastery.

Architectureal fantasy quarter of Rome.

Once the legendary capital of the Dacian Kingdom, this city has been reduced to mere ruins.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

A medieval church built up to defend its village.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.