Global demand for opals is soaring ... "This is the hole," says the 45-year-old. Mr Stutley's mining partner, Richard Saunders, who seems eternally caked in dusty soil, mumbles in agreement.

Welcome to Coober Pedy, the town that lives underground. What began in 1916 as perhaps the largest opal mining operation in the world has since expanded into a subterranean community that is ...