Caving. Spelunking. Underground exploration. Whatever you want to call it, that's what we do. And if you like the outdoors and have a bit of an adventurous spirit, you might like caving too. Officially, we're called the Greater Houston Grotto, and we're a local branch of the National Speleological Society (NSS). As a group we try to study, explore, and conserve cave and karst resources. Oh, and we like to have a little fun along the way! Our members include students and teachers, retire …