Underwater caves are natural formations found beneath the surface of water, often created by the erosion of rock over thousands of years. These caves can be filled with freshwater or saltwater and may connect to larger bodies of water, such as rivers or oceans. They are typically formed in limestone or other soluble rocks, leading to unique geological features. Exploring underwater caves can be challenging and requires specialized equipment and training, such as scuba diving gear. These caves are home to diverse ecosystems, including unique species of fish and microorganisms, making them important for scientific research and conservation efforts.