NPR's Howard Berkes reports on Kartchner Caverns near Tuscon, Arizona. They were discovered 25 years ago by two young cavers who realized the caves might be destroyed if their existence became known. So they kept it a secret, shared only a few years later with the family that owned the property. Eventually they decided the caves must be developed in order to save them from becoming damaged. They're set to open as a tourist attraction next month. (8:35)
Take a look at photos of the Caverns at NPR's Kartchner Caverns Web page.