A centuries-old lookout post still sits atop a natural stone spire.

The true depths of these stunning Moroccan caves are unknown.

Haunted tuberculosis hospital built by the patients.

A chunk of the "true cross" is held in this small Portuguese church where modern day exorcisms are said to be common place.

A five-square-mile slice of Spain on the Mediterranean coast of North Africa.

This star-shaped military outpost is now simply trying to protect itself from neglect.

A mythical garden that once grew the golden apples of wisdom is said to have existed in this ancient Moroccan city.

This abandoned, turn-of-the-century astronomy hub is now the subject of more photographs than it ever took.

The highest peak in mainland Spain is said to be the final resting place of a Muslim king.

Bold black and white motifs of life and death add a dramatic flair to this 17th-century crypt.

This abandoned mansion has a window for every day of the year, and is a temple for ghost hunters.

A Spanish town built into the cliffs.

Moorish signal station on a stratgic rocky outcrop.

A house covered entirely with shells.

Holding the current title of "biggest chair in the world," it stands with little fanfare in Lucena, Spain.

Rare karst landscape eroded from a flat seabed.