Since the 1980s, archaeologist Jan Simek and his colleagues have surveyed prehistoric artwork decorating the deepest reaches of caves, including the so-called “Unnamed Caves,” of Tennessee and Alabama. (To read in-depth about this work go to, "Artists of the Dark Zone.") Many of the artworks were incised on the mud walls of these caves. In recent years, Simek and Beau Carroll, lead archaeologist of the Eastern Band of Cherokee Indians Tribal Historic Preservation Office, have also studied inscriptions Cherokee left behind in the caves using their own writing system. Below are images of some of these artworks and an inscription taken by photographer Alan Cressler. (All images are courtesy of Alan Cressler. To see more, go to Cressler’s Flickr.com site.)