Umoona Opal Mine & Museum,
Coober Pedy, SA
There's a relaxed and friendly vibe in Coober Pedy, where 3,500 residents from over 45 different countries have literally gone underground to avoid the searing outback heat. Most people work in the opal fields but their quirky underground community - complete with a church, hotels and a grassless golf course - has made tourism the second biggest industry.
Discovered in 1913 by 14-year-old Willie Hutchison, Coober Pedy takes its name from the Aboriginal word kupa (uninitiated man or white man) and piti (hole). Today its 70 fields cover almost 5,000 square kilometres and produce most of the world's opals.