This centuries-old tower hosts endangered bald ibis mating pairs and looms over a pristine beach.

Dead weights honor the dead of Portugal's fishing industry.

At night, bats patrol this magnificent 18th-century space in search of book-eating pests.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

One of the oldest and largest wooden churches in France was very evidently constructed by shipbuilders.

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

This ghost town in Belgium will lose its street art when it ceases to exist.

Take a leisurely walk through the park to find the seven giant troll sculptures hidden throughout the park.

This uber-quaint Polish village is known for its habit of painting elaborate floral motifs on just about everything.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

This massive collection of taxidermy is full of specimens collected by missionaries during their international travels.

Nestled in the woods lies this land art project: a hybrid between park, maze and natural monument.

This miniature take on the Kremlin is one Dutch man's retirement project.

Mosaics created from 11 million cigar bands.

A Spanish town built into the cliffs.

Peek into a cave of giant, glimmering crystals.

An enchanting landscape of ancient sandstone structures eroded into otherworldly shapes.

Originally planted by the ancient Carthaginians, this sprawling palm grove is one of the largest in the world.