Diving in an abandoned lead mine may seem like a madder version of spelunking. It's not. "There was no blueprint on how to operate anything like this," Goergens says. "We developed the standards for operating the mines, and those standards have been adopted worldwide by other dive resorts. We're ranked as the safest scuba-diving operation in the world. We supply personnel to run these trips. Most dive places throw you in the water -- maybe with one other diver, maybe not. Our average staff person has to go through a year of courses to work down in the mine." National Geographic may have picked Goergens' resort as one of the Top 10 adventures in the U.S., but anyone with the an interest in diving will find a patient, professional and warm staff, who never take unnecessary risks and who know the mines as well as the men who carved them out of the stone. The curious can take a virtual plunge at www.2dive.com or visit West End Diving out on Natural Bridge Road. Best, though, to make the hour drive south to Bonne Terre and take the walking tour yourself. Beats Rock City and the Mystery Hole.