Wind Cave

Wind Cave was found in the late 1800's by a couple of boys who were riding along and noticed the plants moving in front of a hole in the ground.  One of them put his hat by the hole and it blew away!  He came back later, put his hat in front of the hole again, and it was sucked into the cave, never to be seen again.  This hole is still the only natural entrance they've ever found.  And they've mapped out 138 miles of cave.

We descended 300 stairs.  These stairs and concrete walkways were constructed by the CCC in the 1930's and 1940's.  They took the concrete down in cut up inner tubes.  The inner tube held enough concrete to make 1/3 of a stair step.  That's a lot of trips!

We saw cave features like popcorn:

and boxwork, named because it looks like post office boxes:

Wind Cave has over 95% of the world's known boxwork formations.

It was 53 degrees in the cave, so we bought some long sleeve shirts.  I certainly didn't need one, as the humidity was over 90% and the coolth felt good!