Buddhist stupa is the the highest and most prominent structure of Mohenjo-daro, and is located atop the citadel mound. The mound is thought to have housed the elite of the early society and to have been a very sacred part of the ancient city. The stupa was built during the Kushan Empire, 1st to 4th centuries CE, while all of the other excavated ruins are from 2,600-1,900BCE.