Kentucky
Kentucky is best known for it's rolling green grass hills that gave birth to Bluegrass music and bourbon distilling. The limestone karst topography that underlies the hills and knobs of this unique landscape hold a bigger secret found in Mammoth Caves National Park, the world's longest subterranean cave system. With a little over 400 miles currently surveyed, Mammoth Caves is one of the easiest caves systems to explore as the park features over 14 miles of established trails.
