Shatter Cave’s entrance forces visitors to bow down to its geological wonders — or at least forces cavers to crawl through a concrete tunnel on their hands and knees. Once inside, where the walls sparkle and giant bacon strips of minerals hang overhead, it’s clear why novice cavers usually aren’t allowed in Shatter Cave: Not only is everything eerily beautiful here, it’s also very, very old. Shatter’s tight squeezes are no match for Gina Moseley, a paleoclimatologist at Austria’s University of Innsbruck who’s been caving since she was 12. Today she is hunting for 30,000-year-old crystals that formed when permafrost melted in the last Ice Age.