The hole in the cliff before you is not a true solution cave, but a slump-block cave.  Solution caves are formed by slightly acidic groundwater dissolving soluble rock from the sides of crevices as it passes and enlarging them into chambers.  Slump-block caves are formed when a large blocks of rocks are separated from the bedrock by either undermining or groundwater solution along intersecting crevices.  Instead of falling away from the cliff, they lean toward it, forming a passage.  The large block of rock to the left of the opening is slump-block that made this caves, as shown by the slight tilt of the layers of rock forming it.

 This is the only cave in the preserve which is part of the trail system.

 Please do not enter any other caves you may see.  They have been closed to public use in order to protect the bats, amphibians and other creatures which live in them.