Only in Jerusalem! While digging a deep service shaft to serve the new light railway about to open in the city, a large cave was discovered that appears to be an important, ancient water source. Hebrew University of Jerusalem researchers recently completed an initial survey of the water source in the cave, whose full length has yet to be explored.

The cave is narrow and a few dozen meters high, forming an underground canyon. It contains an underground stream, flowing in a southeasterly direction. It is a type of karstic cave, which refers to an area of limestone in which dissolution has produced sinkholes, underground streams and caverns. Karstic caves are common mainly where the climate is wetter, such as Slovenia.

The length of the cave is believed to extend for several hundred meters, at least, though its true length will only be known after subsequent explorations. At a distance of some 200 meters from the service shaft, the Hebrew University cave explorers found a series of small waterfalls. Testing of the water in the cave, it is believed, can yield valuable information about potential pollution of the underground water supply in the Jerusalem area. 

“This cave is the largest and most impressive of its type that has yet been found in Israel,” said Frumkin.  He pointed out that the cave is situated in an area about which there is uncertainty regarding the direction of the flow of water in the mountain aquifer, and this cave can assist in achieving a better understanding of that phenomenon.

Frumkin cited the law that requires preservation of the cave for future generations, but said that this should be feasible for the most part without harming the work on the construction of the new train station.