This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

Ancient ruins hidden underneath a modern luxury hotel.

Fortified medieval tower house with lovely roof garden.

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

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

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

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

2300-year-old Roman road connecting the empire.

The underground sanctuary of a mysterious ancient cult.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The stones of this formerly witch-obsessed castle were used to build a church.

The world's tallest church tower reveals a spectacular view to anyone up to the task of climbing the daunting staircase.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The fairy tale castle of the "fairy-tale king."

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

Mysterious 500-year-old tapestries depict a unicorn hunt.