Mammoth Cave

Hidden Wonder: Mapping Mammoth Cave
Mammoth Cave National Park
This in depth look at the process of mapping Mammoth Cave takes viewers deep underground into the worlds longest cave system. This film can be seen playing in the exhibit area of the park visitor center.
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, 
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Copyright in U.S. Government Works
Mar 8, 2023 — U.S. government works are in the public domain (i.e., not protected by the U.S. Copyright Act). You can freely use them (in a copyright sense
https://www.nps.gov/media/video/view.htm%3Fid%3DAEE5DD73-BABF-4F9C-947F-37EE77F2D784