We have friends there who recently told us about a town in the Australian desert that is mostly underground. Coober Pedy (which literally means ‘white man in a hole’) is an opal mining town with about 1500 residents most of whom live in underground dugout homes. About 90% of the homes and businesses are underground to escape the hot temps. It may be over 120 degrees outside but inside is a comfortable 70 to 75 degrees with no air conditioning required. They showed us a video… very nice homes!