Over 30 mn people in China live in caves
More than 30 million people in China live in caves, called ‘yaodong’ in Chinese, most of which are in the Shaanxi province. The porous soil in the mountainous region is easy to dig, allowing people to build energy-efficient homes. A typical one-room cave is rented out for around $30 a month, while purchasing one with three bedrooms costs around $46,000.