Two very green residential towers cleaning the air in one of Europe's most polluted cities.

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

A complex, nine-layer maze on the grounds of a Venetian doge's playground.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

Pilgrimage site for star-crossed lovers.

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

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

Go inside to really appreciate this 500-year-old technological masterpiece.

This 16th-century monastery has been turned into a surrealist architecture compound.

Geothermal waterfalls in Tuscany.

Thousands of well-dressed mummies below a monastery.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A 16th-century horror show built in a lovely Italian garden.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This hidden Art Nouveau courtyard is an opulent feast for the eyes.