Outside Saudi Arabia’s capital Riyadh, just north of the village of Shawiah and the Dahna dunes, there is Dahl Murubbeh, also called, Profitable cave (Arabic: كهف المربح), Crystal Palace Cave, Quad,B-7, Treasure Dahl 7 (Arabic: كنوز دحل ب7), and more commonly Dahl Shawiah (Arabic: دحل شوية) is a large cave located in the center of Western Asia. Throughout its history, Dahl Murubbeh, along with the other dahls, are believed to be home to jinn, in particular ghouls.
The cave features a large collapsed entrance. At the opening, there is a warm breeze, only slightly cooler than the desert’s blistering 115-degree temperatures, that comes from the depths of the cave to the entrance. The intricate quill-like crystal helictite on the walls and ceiling give the cave the name of the Crystal Palace.
Dahls, Arabic for pits or sinkholes, are prominent in Arabian culture. From Pre-Islamic times to the tales of 1001 Arabian Nights, dahls have been a featured aspect, alluding to the vast unknown. In Arabian lore, caves are believed to house Jinn; generally to lower jinn, such as ghouls. Below is an exert from Aramco World, discussing the presence of Jinn in Murubbeh Cave:
"Locals told us that the dahls were thought to be home to jinn, spirits best left alone by humans. I was reminded of this belief when I squeezed down into one very tight hole. I was halfway down the cable ladder, swinging to and fro inside a large, almost round room, when I heard what sounded like a distant moan. I followed the sound, crawling through a small opening on my hands and knees into a long, low tunnel with smooth, almost white, walls and a floor of soft red sand. The farther I made my way into it, the louder the strange wailing grew and the more beautiful the passage became, until it seemed that every bit of the ceiling was covered with curling, ivory-colored cave deposits. It looked like an upside-down stage crowded with hundreds of beautiful, but out-of-step, ballerinas. In the last room was a sort of alcove and, in the wall above it, a small hole about three inches in diameter...
I poked my smallest flashlight through the hole and looked over it into a bizarrely decorated room...
Eventually, we managed to tunnel through the soft sand under the wall of the 'closet of the jinn,' but could go no farther."
Bones, Tooth-Marks and Ghouls
Throughout Murubbeh Cave, there are passages full of thousands of bones; all mixed together. From carbon-dating, the oldest bones date to over 1200 years old, and the newest human remains date to the early 17th century.
Preserved inside the cave are huge quantities of bones. These bones are from a variety of species, and they include camels, horses, gerbils, gazelles, and humans. These bones, including human remains, are believed to be carried in by some sort of predator creature, some of them bearing tooth-marks.
There has been some debate over what carried all these bones into the cave. Some have proposed hyenas, while others have argued foxes or jackals.
Among the locals, there is the belief that ghouls are responsible for this feat. They argue not to venture too deep into the caves, for fear of a harmful encounter with these wrathful jinn.