There are more than 1,600 documented caves in Arizona, and much of that documentation has come from Arizona Cave Survey, a group of caving enthusiasts who've built up an impressive library and database on the subject. The library consists of books, maps, photos, and even a cave location GIS system, making it an incredible resource for cave researchers. From Lava River Cave in northern Arizona to Colossal Cave in Tucson, ACS has all the information a researcher needs. But novices beware: ACS is also concerned with the preservation of our state caves and will not give out cave locations to the general public, referring inexperienced cavers to local chapters of the National Speleological Caving Clubs for some background and education first. But seasoned cavers who contact them might get some assistance (after their references are checked), and provided they're not looking to explore a "sensitive" cave — i.e., a cave that may be hazardous or is easily damaged, for which ACS divulges no information.