Boxwork formation in Wind Cave National Park.
It's created from thin calcite.
Wind Cave has over 127 miles of passages and is the
third longest cave in the United States and fourth
longest in the world!
Boxwork formation in Wind Cave National Park.
It's created from thin calcite.
Wind Cave has over 127 miles of passages and is the
third longest cave in the United States and fourth
longest in the world!