Ancient cave houses found in China

BEIJING, Jan. 28 (UPI) -- Chinese archaeologists say they've found ancient cave houses that may be the earliest made by man.

A row of 17 cave houses was found on a cliff along along a river northwest China's Shaanxi province, Xinhua news service reported Wednesday. Scientists say the houses were built between 3,500 and 3,000 B.C.

Wang Weilin, deputy director of the Shaanxi Archaeology Institute, said the cave houses appear to belong to a late Neolithic culture called Yangshao. Wang said archaeologists also found pottery kilns, fragments and tools.