Mammoth Cave NP (KY), July 3-4

Natural Entrance to
Mammoth Cave

Mammoth Cave National Park is in Kentucky.  Like other caves I've visited, slightly acidic water has dissolved away limestone to create the cave passages.  Mammoth is different because much of it has a cap of insoluble (waterproof) rock on top it it that keeps water from seeping through from the surface.  So, this cave was formed by slow moving underground rivers and, for the most part, does not have the "decorations" like stalactites or stalagmites.

Inside Large Room in
Mammoth Cave

"Mammoth" is a fitting name for this cave because it is the longest cave in the world at 360 miles.  And, they are discovering more and more of it each year with no end in sight!   What's also amazing is that the 360 miles of cave are under 8 square surface miles of land.  The cave is like a bunch of spaghetti as it goes deeper and deeper.

I went on a hike through the cave's natural entrance.  The rooms I was in were very large.  But, the rangers say that some of the passages are so tight that you have to take your hardhat off to wiggle through them.  It was a hot and muggy day and the cool of the cave was very welcome.   Once back on the surface, I could feel the cave breathing out its cool air ... within a few more feet away from the entrance, I was back in the heat ... fascinating 

I also took a guided tour to a part of the cave that we were bused to.  It doesn't have that insoluble rock cap on top of it so water could seep down through the ceiling and dissolve the limestone to make many beautiful cave decorations.  The entrance to this part of the cave was blasted open with dynamite before it became a national park.

originally posted 7/27/10