Caves are known to be dark, deep and sometimes spooky – but some caves are also known for being especially long. Mammoth Cave in the U.S. state of Kentucky is, by far, the longest cave in the world measuring 405 miles (652 kilometers) in length. To arrive at that number, the length of different passageways of the cave were combined.
Multiple caves in the United States
can be found on the list of the top 10 longest caves in the world provided by World Atlas.
Karst rock topography, gentle hills, enough rain and an abundance of plants and animals make U.S. states Kentucky and South Dakota, as well as the Mexican state of Quintana Roo ideal environments for the formation of caves.
The deepest caves in the world can be found in the country of Georgia, which is the home of four caves with depths of 7,257 to 5,774 feet (2,212 to 1,760 meters).