Tennessee is divided into three parts by the Tennessee River. It begins above Knoxville, flows southwest into Alabama and then returns some 230km west to cross the state a second time. The tree parts are:

  1. The Appalachian Highlands
    East Tennessee has a lot of limestone which is karstified. Most caves of Tennessee are in this area, along the Eastern Continental Divide. This divide, running north to south, along the Appalachian Mountains, tells us that all drainage on the Tennessee side will lead to the Gulf of México. On the North Carolina side of the divide, the water flows directly to the Atlantc Ocean.
  2. Interior Lowlands
    are not really low, they are only lower than the Appalachian Highlands. There are the Eastern Highland Rim and the Western Highland Rim with limestone and caves.
  3. Gulf Coastal Plain
    This area between Tennessee River and Mississippi River is flat and is covered by sediment washed down from both the Rocky Mountains and the Appalachians, some areas are covered by loess, a fertile aeolian sediment. However, there is no subterranean drainage, so there are no caves.

Tennessee is definitely a cave State. It has about 8,700 known caves. There are numerous commercial cave (show caves), offically there are nine. Other caves are used for spelunking tours.