Ein Heet Cave is located in Al-Jubail Mountain, about 40 kilometers south of Riyadh in the Kingdom of Saudi Arabia. It is an effortless day out for families and easy for most vehicles to access.
The geological name of this site is a solutional or karst cave, also known as a sink hole. The cave is famous because it is a naturally forming limestone phenomenon. It has a natural water reservoir at the base of a sheer limestone rock face. I am going to guess there are not many natural watering holes like it in Saudi.
A solutional cave forms in soluble limestone and is the most frequently occurring type of sinkhole in these kinds of conditions. It can also develop in other rocks, including chalk, dolomite, marble, salt beds, and gypsum. It is characterized by the underground drainage systems from the surrounding ravines.
The natural acid in rainwater and groundwater in the bedrock seeps down from the mountain and the surrounding countryside's planes, faults, and wadis.
Geological studies have documented these openings that expand as the walls dissolve into an intrinsic cave system. The portions of the cave below the water table or the local level of the groundwater will be flooded year-round. The bedrock is the hard, solidly packed material that remains once you remove the loose surface material.
Heet Cave is a well-known undeveloped tourist site and one of Saudi Arabia's more easily accessed underground caves. It is home to a lake in internal circled holes more than 30 meters deep and 150 meters long in this particular cave. The water level was high in the past. However, the water levels have declined in recent times due to the unpredictable rainfall in the region.
The cave consists of numerous interlined sinkholes. The cave's opening serves as a giant gaping echoey space leading to a large groundwater reservoir dating back thousands of years. The cool temperature of the water and the cave atmosphere distinguishes the cave due to its limestone formation.
Since 1938, the Ein Heet cave has been known as a source of minerals such as anhydrite. Due to the curious mind of King Abdulaziz Al-Saud, a study was undertaken with the assistance of visiting geologists. The study revealed the first anhydrite rocks in the kingdom.
"At that time, several experienced cave explorers visited Ein Heet cave with their heavy equipment. The researchers reached the edge of a lake situated 120 meters under the surface by using scubas. According to their point of view, this cave has pure water, and it is the most pristine water in the world".
Hence the high number of people willing to take a dip to wash off the day's dust. I wouldn't encourage that activity for safety reasons. But you can pack your picnic, camera, and walking shoes for a fun day out in the area.
