"Alleys of Stone" form natural mazes in Spanish natural park.

Geological storytelling.

Cliffside houses provide a spectacular view from their perch above the valley.

Walls of stone rise up from sinkholes caused by underwater erosion.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

The prolific artwork of a self-taught sculptor.

A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

The streets of a sleepy Spanish town proudly exhibit some of the world's finest graffiti.

This ancient rock painting is the oldest evidence of humans’ love affair with honey.

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

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

Stuck in the middle of a modern Madrid city block are the remains of a 19th century sports complex.

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

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

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

100-windowed castle turned art gallery, built by one dedicated mason.

Historic medieval fortified city in southwest France.

700 iron sculptures crammed into a Mediterranean park.

A public park off the beaten path with a beautiful waterfall and 13th century Cistercian abbey.

Haunted tuberculosis hospital built by the patients.

The world's first electric battery-powered submarine.

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