Dev­ils Tow­er is a dra­mat­ic geo­log­ic fea­ture that juts out of the rolling prairie sur­round­ing the Black Hills region in Wyoming, and it became the first nation­al mon­u­ment in the coun­try in 1906. It might seem like a majes­tic moun­tain, but it’s actu­al­ly made of molten rock that hard­ened into fas­ci­nat­ing geo­met­ric columns. This site is sacred to mul­ti­ple Native Amer­i­can tribes, and its myth­i­cal qual­i­ty led to it being fea­tured in the sci-fi movie “Close Encoun­ters of the Third Kind.” It’s still the set­ting for Native Amer­i­can cer­e­monies as well as a pop­u­lar des­ti­na­tion for rock climb­ing and hik­ing.