Resolution: 1/2 - Click the region of interest for enlargement.
Image rights
River Styx, a partly subterranean waterway, emerges onto the surface in Mammoth Cave National Park. Author Daniel Schwen. Created 25 November 2007. Accessed through WikiCommons. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License. This file is licensed under the Creative Commons Attribution ShareAlike 3.0 License.