DESERT  SPELUNK 

Dave asked if we would like to join him on a day trip to a desert cave.  We would need to bring warm clothes, flashlights, and shoes for wading.   We quickly agreed, knowing Dave’s trips were usually adventures.  This trip would be no exception.

It sounded intriguing.   A cave in the endless desert of the Eastern Provence of Saudi Arabia was hard to imagine.  How could there be a cave in the sand?  And shoes for wading?  Saturday arrived, overcast and cool.  We packed gear and lunch into our land-cruiser.  Dave had invited another couple to go with us. We assembled in front of our apartment building.  Our two vehicles followed Dave’s jeep out of town on the coast road toward the oasis of Hoffuf.  Around halfway to the oasis, Dave turned off the highway and headed East.  We followed him on sand tracks.  After a slow drive on packed sand, we approached a unique sand dune.  It was uniform in height.  It curved away in both directions. It appeared to be composed of rubble rock rather than of sand like most dunes.  We followed the track up to the top of the dune.   From the top of the dune, I could see that this was our destination.  The dune formed a ring enclosing a crater.  The crater was about a  mile in diameter.  Inside the ring, the crater floor sloped gently to the center.  We followed Dave’s jeep down the interior side of the crater.  Dave drove to the lowest spot.  We stopped near a depression at the center of the crater.  

The crater had most likely been caused by the impact of an asteroid in the distant past.  The infrequent but heavy desert rain storms had scoured a drain at the center of the crater.   It was for that strange hole in the floor of this crater, that we had come.  Ever a scientist, Dave’s mission was to release bottles with notes in them describing his attempt to discover the outflow of this cave system.  Should someone find one of these bottles they were to contact him at King Faisal University.  He had a bag of bottles which he was going to place deep in the cave where they would not float back to the opening,  but would be washed out to some distant place.  Perhaps they would be found on a beach along the Arabian Gulf, or at an oasis. It could be that tube emptied under the sand in the vast expanse of desert that surrounded the crater, in which case his bottles would never be found.    

 Taking our flashlights we approached the depression.  It was 60 feet in diameter with sloping sides formng and inverted cone. At the bottom of the funnel was black rock.  It struck me to be like a large version of an ant lion’s sand funnel trap.  Pointing down the funnel to an opening in the rock. My ten year old daughter, Monica, asked Dave “Are we supposed to go down there?”  Dave replied “I was down there a couple of weeks ago. We can do it.”  Monica declared “I’m not going.” Dave explained “We only need to go far enough into the cave to release the bottles.   My two sons wanted to go with Dave so I was obliged to go along.  Dave’s friend also agreed to go, But his wife stayed on top. with my wife, Maura, and Monica.  

The sky was overcast as we descended down the slopes of the ant trap leaving the two women and my daughter with the vehicles.  We descended down funnel to a point about 40 feet below the floor of the crater.  There, cut into black stone, possibly fused by the asteroid’s impact, was the opening into the “cave”.  We entered the cave. It was dark, we turned on our flashlights and continued.  The tube varied in diameter. For most of the way, it was around 5 feet in diameter.  It was steep at first not unlike climbing down a ladder with protruding rock steps.  After descending about 50 feet the slope of the tube became more gentle.  By this point, I was convinced that we were not going into a cave, but rather into a natural drain pipe, through which great volumes of water flow when it rains.

 Eventually we came to a place where we were wading in ankle deep water.  Water usually does not stand in the desert for long.  This stone was dense and the water which was standing in the lower sections of the tube was probably there from the most recent rain.   We proceeded for about 200 feet.  Along this section, the tube was about 7 feet in diameter. It would rise slightly and then slope down again.  Sometimes we waded at other times we walked on dry gravel.   We eventually came to a place where the tube became smaller.  Here it was barely large enough to crawl through.  It was here that I decided I would go no further.  My boys both wanted to continue.  Confident in Dave’s knowledge and abilities, I let my two boys go with him.  It would have been difficult to convince them that they should not continue on such a big adventure.  Before turning back I watched as they each crawled into the narrow passage on hands and knees with heads down. The tube curved ahead of them and soon they disappeared into the blackness. My son later reported that the narrow part of the tunnel was so tight that they could not turn around when Dave decided that they had gone far enough. They had to crawl backward. My youngest son, who had been the last in the column became the leader in their backward crawl to the larger section of the cave.

Seeing them disappear into the narrow tube,  I turned and made my way back up and out of the tube. I made my way up the sandy slope of the funnel and onto the crater floor.  The two women and my daughter were there with the vehicles.   A light rain was falling.  The kind of light rain which comes to the desert just before a down pour.  I Panicked.  I told Maura that I was going back down to warn the others of the rain.  I quickly made my way down the sloping sides of the “funnel” and into the pipe which I was convinced would soon be flooded with rushing water.  When I reached the first wading section where the slope of the pipe became more gentle  I stopped.  I thought I heard a voice.  I turned my flashlight off.  As my eyes adjusted to the absolute blackness, I could see the faint glimpses of light coming from further down the pipe.  Soon distinct voices could be heard.  Then flashlight beams came into sight.  I shouted that it was raining up on top and we needed to get out quickly.  We made our way out before my imagined floods came washing down from all sides of the crater to fill the tube and wash everything in it away.  

We exchanged our goodbyes, climbed into our vehicles, and followed Dave on the track which led up over the sides of the crater and out.  Soon we were back on the highway to the little town of Al Khobar and the safety of our apartment.  Dave’s bottles were never found.

Copyright December 2022 by Theodore “Tod” Lundy, Architect