The Ayalon Cave is a large underground limestone cave located near Ramla, Israel, discovered in April 2006. The cave, 300 feet deep, with its branch extends almost 2.5 kilometres making it the second largest limestone cave in Israel. Researchers announced that they have so far discovered eight new species, all without eyes, including four crustacean species and four terrestrial species, previously unknown to science. They added that the crustaceans included two saltwater species and two freshwater species, indicating that this diversity might help better understand the water history of the region.
The cave was first discovered when a small opening was discerned in a quarry near Ramla. According to Professor Amos Frumkin of the Hebrew University, the cave is unique in that a thick layer of chalk left it impermeable to water.
The cave will remain closed to the public to allow scientific investigation to continue undisturbed.
As the cave was completely cut off from the outside environment, it sustained an independent ecosystem; this ecosystem did not rely on sunlight and photosynthesis, or on organic compounds, for an energy source. Rather, energy was extracted by Chemoautotrophic bacteria, living in a film on top of the pool water. These bacteria produce energy by oxidizing the sulfide compounds in the water, and derive organic compounds using carbon dioxide from the air. These compounds form the basis of the cave's ecosystem.