text: China In north China, especially on the Loess Plateau, caves called yaodongs dug into hillsides have been the traditional dwellings from early times. The advantage of a yaodong over an ordinary house is that it needs little heating in winter and no cooling in summer. An estimated 40 million people in northern China live in a yaodong. Many people live in semi-recessed dugout houses in north-western China where hot summers and cold winters prevail.
  Japan
  In the Early Jōmon period of Japanese prehistory (10,000 to 300 BC) complex pit houses were the most commonly used method of housing.
  Middle East
  Israel
  During the Bar Kokhba Revolt, Jews used an intricate system of man-made hideout complexes, prepared well in advance of the onset of the revolt. Many such sites were discovered in Judaea and the Galilee, for instance at Horvat 'Ethri.
  Turkey (Cappadocia)
  Cappadocia contains at least 36 historical underground cities, carved out of unusual geological formations formed via the eruptions of ancient volcanoes. The cities were initially inhabited by the Hittites, then later by early Christians as hiding places. They are now archeological and tourist sites, but are not generally occupied (see Kaymaklı Underground City). The latest large Turkish underground city was discovered in 2007 in Gaziemir, Güzelyurt. This city was a stopover on the Silk Road, allowing travelers and their camels to rest in safety, underground, in a 'fortress' hotel equivalent to a modern hotel.
  Europe