"Another theory says the underground city served as a temperate refuge for the region’s extreme seasons. Cappadocian winters can get very cold, the summers extr

"Another theory says the underground city served as a temperate refuge for the region’s extreme seasons. Cappadocian winters can get very cold, the summers extremely hot. Below ground, the ambient temperature is constant and moderate. As a bonus, it is easier to store and keep harvest yields away from moisture and thieves." Some Aussie opal miners already took note.