This small and often-overlooked museum holds some of Spain's finest artistic treasures.

A lush indoor jungle fills this bustling Madrid transportation hub.

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

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

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

An unusual but excellent display created in the 1930s as propaganda against the Freemasons.

The facade of this 16th-century building is decorated with carvings of 300 seashells.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

Whether they are bulls or pigs, these ancient animal sculptures are fascinating relics.

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

Nestled in the hills of Tuscany are gorgeous, multicolored hot springs.

A lavish 16th-century mansion filled with spectacular staircases, fantastic frescoes, and gorgeous gardens.

Largest necropolis in the Mediterranean.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

A popular legend claims that the famous pizza was invented at a restaurant in this alley.

This monumental fountain has moved around the city multiple times.

Before the more famous Royal Palace of Caserta, the king of Naples first commissioned this overlooked residence.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This clifftop arch is a natural stunner.

This stately palace, first built in the 16th century, was converted into a prison in 1830.

Roman ruins top white travertine terraces formed by ancient hot springs.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

A Turkish ghost town abandoned in a population exchange with Greece.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.