Limestone caves are natural underground formations created by the dissolution of limestone rock. This process occurs when slightly acidic water seeps into the ground, gradually eroding the limestone and forming various features like stalactites and stalagmites. These caves often have unique ecosystems and can be home to various species of bats and other wildlife. The formation of limestone caves can take thousands to millions of years. They are commonly found in regions with abundant limestone deposits, such as the Appalachian Mountains in the United States and the Carlsbad Caverns in New Mexico. These caves are popular for exploration and tourism, attracting visitors interested in geology and natural beauty.