The youngest volcano in Central America.

A Mayan village preserved for centuries in volcanic ash.

Antoine de Saint-Exupéry's 1943 book shares a surprising connection with El Salvador.

This color-changing crater lake in El Salvador is occasionally impenetrable to sunlight.

A legendary tree towers within its own vibrant sanctuary.

This tribute to the fictional detective stands at the famous literary character's address.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

A medieval, mosaic-lined baptistry built by a heretical Christian sect.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

The world's largest "Christmas tree" is illuminated by hundreds of lights stretching 2,000 feet up the slope of Mount Ingino.

A massive engineering and hydraulic marvel dating back to the 3rd century BC

Medieval streets buried beneath a papal fortress now form an underground city you can walk through.

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

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

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.

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

Medieval torture techniques with a modern conscience.

Geothermal waterfalls in Tuscany.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

Kissing the ass of this stone lioness has become a rite of passage in the city of Girona.

These fly sculptures are scattered around the city and represent the patron saint of Girona.

Designed by Gustave Eiffel before his famed tower.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.