A breathtaking and biodiverse wilderness in the mountain setting of Ernest Hemingway's "For Whom the Bell Tolls."

A magnificent, long-abandoned castle built in the wake of the reconquest of Spain.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

This postmodern apartment block was designed to be a vertical neighborhood.

Madrid's last horchata kiosk is a blue-and-white beacon of refreshment.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

This embalmed man is one of the best preserved mummies from the Canary Islands.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

An ancient Egyptian temple in the middle of Madrid, Spain.

This fascinating and poignant museum chronicles every imaginable aspect of Spanish colonialism in the Americas.

This influential Renaissance-era library was once the haunt of kings and monks.

Claude Monet immortalized this medieval bridge in two of his paintings.

This monastery built into a cliff hides a perfectly preserved hermit in a glass coffin.

Geothermal waterfalls in Tuscany.

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

The world's first underwater farm is home to more than 700 plants.

The highest waterfall in Italy is only "turned on" five times a year.

This half-finished "city of toys" was almost Italy's own Las Vegas.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

Does this strange mural depict witches battling beneath a penis tree?

This former fascist summer camp was abandoned for decades.

This winding road through an Italian canyon may be the most scenic drive in the world.