The caves were used by the Geonosians for thousands of years, serving as shelter from the dangerous radiation on the planet.
During the Second Battle of Geonosis Jedi Master Ki-Adi-Mundi took a squad of Clone troopers to examine a shortcut through the clifftop cave to the rendevouz spot. In the cave, Mundi and his men were besieged by groups of Geonosian soldiers who depleted the clones' numbers by attacking them and carrying them into the depths of the cavern. Although his men sustained heavy casualties and losses from the Geonosians, Mundi was able to cut through the cave. At the other side, Mundi had his Clone flame troopers fire their flamethrowers at the Geonosians, killing most of them and unblocking the path out of the cave.