I found this location via a photo pinned to Google Earth. From the satellite imagery it looked at first to me like a mushroom-shaped rock with a cave in it. That warranted a drive to it and a check out. I took the coordinates and set off with two friends who drove out in a safety vehicle. It is best to take more than one car on these desert treks. We drove out the Dammam Road and then along the Khurais Road approximately 38 km to the turnoff at N24°59.260’ E047°23.882’.
If you have Google Earth or Google Maps you can use it to see the pipeline track plainly before you set off. You will have to get around some construction right at the highway but just a few hundred meters along, you will join the pipeline service road. Follow it on its arrow-straight path approximately 16 km due south to a spot just east of the Geocache. 4WD is nice to have though not required. Notice all the red and purple dirt as you drive south. If you reach the Pump Station at N24°51’00.52” E047°23’41.52”, you will have gone approximately 70 meters too far. Turn west (right) from your track and follow the tire tracks through the red sand and dirt to what I have called the Mushroom Rock Grotto at N24°51’12.14” E047°23’04.13”.
The rock is just off the pipeline route. What is interesting is that there is a cave under it. Since it has obviously been used as shelter for many years I tagged as a grotto. There is evidence of older history and much more modern human users, who we in the states call “taggers”. Their graffiti is all around. I think that most recently either pipeline workers or picnickers have used it. It is noticeably cooler inside. There is no GPS coverage under the 5 meters of rock, of course. We walked and crawled through the cave to a deeper area in the back. No flashlight required. We climbed up and out the rocks from the back and climbed around the rocks to find a good Geocache hidey hole. It seemed to have had too much traffic to leave the Geocache so close to this grotto. The best we could do was to hit on a rock pile approximately 120 meters due west of the grotto. I hid the cache in a recess near the top of the pile and concealed it with three larger stones than you are accustomed to finding for this purpose. The cache is in a plastic food saver container of high quality. I left a pencil and a log, which my two friends and I started on 7 AUG 2015.