Cave systems are natural underground spaces formed by the erosion of rock, often limestone, through water and chemical processes. These systems can vary in size and complexity, featuring tunnels, chambers, and unique formations like stalactites and stalagmites. They provide habitats for various species, including bats and cave-dwelling insects. Cave systems can be found all over the world, with notable examples like the Mammoth Cave in the United States and the Waitomo Caves in New Zealand. They are important for scientific research, tourism, and understanding geological processes, as well as preserving unique ecosystems.