sentences:  The wall surrounding this site was probably to face floods of Sarasvati River, and the wall collapsed due to water damage.Marine shells were found at Banawali as well as at Harappa, Kalibangan, which are far away from sea shore and such findings indicate internal trade between the regions during early Indus period.Seals were only found in lower town and not in citadel;several small stone weights and terracotta plough model was also found.