See this gallery of caverns, cave picturess and canyons. Also, don't miss this BetterPhoto article on digital exposure camera techniques.
Rafting the Canyon panorama
© Stephen A. LivermanArizona Sandfalls
© Kathleen E. Wasselle CroftAncient Sites
© Daniel Schual-BerkeLight at the End of the Tunnel
© MARLON IGNACIOAntelope Canyon
© Sue L. CullumberInside Bryce
© Ken Smith