The cave, which has been dubbed the Ayalon Cave, is “unique in the world,” said Prof. Amos Frumkin of the Hebrew University Department of Geography. This is due mainly to its isolation from the outside world, since the cave’s surface is situated under a layer of chalk that is impenetrable to water. The cave, with its branches, extends over some 2½ kilometers, making it Israel’s second largest limestone cave. It is to remain closed to the public to permit further scientific research.Okay, so its not 6 miles down & there's no Uru city, but it sounds pretty neat to me. I enjoyed these pics of the Ayalon/Ramle area too. (click 1st image. 2nd image links to another article on the same subject.)
The underground cave includes an underground lake, in which the crustaceans were found. The lake is part of the Yarkon-Taninim aquifer, one of Israel’s two aquifers, yet is different in temperature and chemical composition from the main waters of the aquifer. The lake’s temperature and salinity indicates that its source is deep underground.