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.