Kalibangan, ancient site of the Indus valley civilization, in northern Rajasthan state, northwestern India. The site contains both pre-Harappan and Harappan remains, and therein can be seen the transition between the two cultures. Although the pre-Harappan culture worked copper and produced pottery, it had no writing system, and its ruins lack the orderly layout and use of baked brick that is found in the later Harappan sites. The Harappan remains include a cemetery and a fortified citadel.