Mammoth Cave, which has connecting passages covering over 400 miles on three levels. Kentucky also has the second greatest length of navigable waterways in the US (Alaska has more), and the two largest manmade lakes east of the Mississippi River.
Kentucky Bend completely surrounded by Missouri and Tennessee. Cumberland Falls, in the southeastern part of the state, is the only place in the western (and northern) hemisphere where a moonbow, formed by the light of a full moon shining through mist at the base of the falls, can predictably be seen.
5. Kentucky was officially neutral during the Civil War. Both Jefferson Davis and Abraham Lincoln were born in Kentucky.