More than half of the 3,500 inhabitants of Coober Pedy, in the heart of the Australian desert, live buried in limestone rock in underground houses called “dugouts” to escape freezing winters, hot summers and occasional cyclones. The temperature can exceed 50 ° in the day and fall around zero at night. But these shelters offer a constant temperature of about 23 °. Often the only sign that you are walking on someone’s roof is an air vent that protrudes from the ground at your feet.
The city is nicknamed the world capital of opal. It attracted many minors seized by the fever of this semi-precious stone in the early twentieth century. Many rich veins have been discovered here and it is said that one could become a millionaire in one day. Today, there are still some stones, some within the homes. The inhabitants use opals found when they dug their house as money, which allows them to enlarge their houses, and thus find even more opals. Digging a new room allows them to acquire all the furniture and decoration of the new room!