A reproduction of the famous prehistoric cave paintings is hidden underground at the National Archaeological Museum.

A lush indoor jungle fills this bustling Madrid transportation hub.

Once a resting spot for King Fernando VII.

The remains of this misplaced church were moved here stone by stone.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

The remains of the second-oldest zoo in Europe can be seen within these library gardens.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Commonly acknowledged as the only public monument to the Devil himself.

A curious memento mori hangs in the magnificent Cathedral of Segovia.

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

According to tradition, King Phillip II supervised construction of the seat of his empire from this seat carved into rock.

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

This Gothic church houses ornate royal tombs and a magnificent gilded altarpiece.

For more than half a millennia, this automaton has rung an hourly bell.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

This remarkable museum sprung from one of the most important prehistoric archaeological sites in the world.

A historic Christian shrine nestled within a spectacular natural cave.

A road that winds through this natural cave is the only way to access the small, appropriately-named village of Cuevas.

A magnificent place to see authentic paleolithic cave paintings that are an astounding 33,000 years old.

Stormy conditions send jets of seawater bursting through holes in the cliffs.

These primitive rock paintings include a very beloved depiction of a woolly mammoth.

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.

This beautiful spit of land was once the summer playground of the king of Spain.

A small church ornamented with medieval erotic sculptures.