Explanation:

Rupnagar is a 21-metre-high ancient mound overlaying the Shiwalik  deposition on the left bank of the river Sutlej where it merges into the plains. It has yielded a sequence of six cultural periods or phases with some breaks from the Harappan times to the present day. The excavations were carried out by Dr. Y.D. Sharma of Archaeological Survey of India. The migration of the Harappans to Rupnagar has been postulated through the lost Saraswati River to the Sutlej as both rivers once belonged to one system.