For generations, people have retreated to caves when faced with war, persecution, poverty, or a harsh climate. They’ve chiseled through rock, burrowed deep into the earth or moved into what was naturally there, to find some escape from the less favorable conditions outside.

Relentlessly extreme climates compelled some communities to make their homes in caves, where the environment stays reliably temperate. The residents of the Coober Pedy mining town in the Australian Outback settled underground to avoid the intense desert heat. Similarly, the people of Guadix, Spain, carved their homes out of hills.

Caves also provided protection during times of war. Early Christians fled to the caves of Cappadocia to escape persecution and the wrath of Rome. Mao Zedong used