Now knowing that we wanting to visit all of the 58 American National Parks, we took the opportunity during the Labor Day weekend in 2010 to drive to Kentucky and enjoy Mammoth Cave. It was our 15th canceled park.

The cave was enormous in size. It is the world’s longest with about 400 miles already explored. It is twice as long as the second longest cave on Earth. Mammoth Cave was mainly formed with limestone rock and has five layers due to flooding. All this happened millions of years ago.

Amazingly, there is life inside of the cave. In a world under the Earth, completely quiet, dark and eerie, insects like cave crickets and spiders are hanging out on the rocks. Conversely, it was so gorgeous outside that we went for long afternoon hike. The countryside was so beautiful. We journeyed to The Green River.