Known as much for the way most of its 1,700 inhabitants live—underground in dugouts gouged into the hills to escape the relentless heat—as for its opal riches, Coober Pedy is arguably Australia's most singular place. The town is ringed by mullock heaps, pyramids of rock and sand left over after mine shafts are dug.

Opals are Coober Pedy's reason for existence. Australia has 95% of the world's opal deposits, and Coober Pedy has the bulk of that wealth; this is the world's richest opal field.

Coober Pedy is a brick-and-corrugated-iron settlement propped unceremoniously on a scarred desert landscape. It's a town built for efficiency, not beauty. However, its ugliness has a kind of bizarre appeal. There's a feeling that you're in the last lawless outpost in the modern world, helped in no small part by the local film lore—Priscilla Queen of the Desert, Pitch Black, Kangaroo Jack, and Mad Max 3 were filmed here. Once you go off the main street, you get an immediate sense of the apocalyptic.