They may not have as many number one hits as Elvis, The Beatles, or the Rolling Stones, but these rock stars have been around for more than 400 million years and go by stage names like sandstone, shale, chert, and novaculite. From their meager beginnings in the Carboniferous Period to the height of their fame atop the Ouachita Mountains, go backstage and get the real dirt on Hot Springs geology at “Spa Rocks!”, a hands-on look at the rocks, minerals, and mountains in the Hot Springs National Park.