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

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

These ungulates have quite literally bounced back from the brink of extinction.

A spectacular walk on the flank of a gorge.

A historic Christian shrine nestled within a spectacular natural cave.

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

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

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

A wonderful collection of fossilized dinosaurs and other creatures that roamed the landscape millions of years ago.

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

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

The largest underground church in Europe.

According to myth, Zeus himself was hidden in this cave to escape being eaten by his dad.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

An ancient octagonal weather station named for the eight Greek gods of wind.

Large collection from the 3rd millennium BCE.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

The most famous location in China was home to whole dynasties worth of imperial rulers.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

Model Trains and Much More in Hamburg.

Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

The once highest point in China blends symbolic design with a kick of adrenaline.

This abandoned Greek island was the last active leper colony in Europe.