Yaodong

A yaodong (窰 [iɤ] in native Jin Chinese, or 窰洞 [jɑʊ tʊŋ] yáodòng in Beijing Mandarin) is a particular form of earth shelter dwelling common in the Loess Plateau in China's north. They are generally carved out of a hillside or excavated horizontally from a central "sunken courtyard". The surrounding earth acts as a natural insulator, keeping the interior warm in winter and cool in summer. Consequently, very little heating is required in winter, and in summer, it is as cool as an air-conditioned room. The history of yaodongs goes back centuries, and they continue to be used. However, they are unsafe in earthquakes. During the 1556 Shaanxi earthquake, some 100,000 people died, mainly because large numbers of yaodongs collapsed. As of the early 2000s, between 30 and 40 million people in northern China still lived in yaodongs, a number rapidly decreasing as millions move to more modern dwellings nearby or move away as part of urbanization in China.