Cave?

We stopped at Graham Cave State Park.  I was expecting to see a little cave but one with some dark corners to investigate.  Instead we found an open cave that was mostly fenced off so we couldn't enter and was partially filled with gravel.  In the past an archeological team investigated the cave and found various Native American traces.  If they have already done a full archeological dig, I don’t know why the fencing and gravel was done.  Basically, it's pretty boring and I wouldn't recommend visiting.

On the bright side, I found an interesting tree nearby.