This story appears in the April 2013 issue of National Geographic magazine. Tusk and Sunset A mammoth’s tusk spikes the Siberian sky on Bolshoy Lyakhovskiy Island. Tusks that are discovered with ...

This story appears in the January 2011 issue of National Geographic magazine ... There are longer caves than Hang Son Doong—the Mammoth Cave system in Kentucky, with 367 total miles, holds ...

National Geographic has published ... according to the magazine. According to the National Park Service, entrance to Mammoth Cave National Park is free, but access to the variety of guided cave ...