In late prehistory, the Pyu settled for quite some time in Beikthano in the Yin River Valley than the Nawin River Valley at Sri Ksetra, because they proved their skills of water control using irrigation systems depended on their good knowledge of the conditions in each locality and area. According to Stargardt in “From the iron age to early cities at Srikestra and Beikthano, Myanmar” Journal of Southeast Asian Studies, all the archaeology found a lot of major inscriptions on stone in phy language survive at Sri Kestra (Pyu), Hanlin and near Pinle (Hmainmaw), and Bagan. They have strong evidence on the people were living in that century between the third-fourth and fifth-sixth centuries CE. All the record was nominated by World Heritage UNESCO and other historians. In this article, it mentioned and written also "Pyu" were among the earlies people in Southeast Asia. As Stargardt acknowledges in that article, "Sri Kestra" contained fields, irrigation canals, water tanks and iron-working sites, as well as monuments, markets (and elusive habitation areas) both inside and outside walls, all these halls also provide evidence of a powerful belief system in the elaborate provision of the dead”. In that article, the author adds upon his research in other's article, they also recorded old photo of founded place which is already surveyed in nine major burial terraces outside the southern city walls, old Buddhist monuments including the complex at "Beikthano" city and the queen "Panhtwar" cemetery. Archaeological surveys have actually so far unearthed 12 walled cities, including five large walled cities, and several smaller non-fortified settlements, located at or near the three most important irrigated regions of precolonial Burma: the Mu River Valley in the north, the Kyaukse plains in centre, and the Minbu region in the south and west of the former two. The city-states were contemporaries of the Kingdom of Funan (Cambodia) and (perhaps) Champa (southern Vietnam), Dvaravati (Thailand), Tambralinga and Takuapa near the Kra Isthmus, and Srivijaya (southeast Sumatra). All these statelets foreshadowed the rise of the "classical kingdoms" of Southeast Asia in the second millennium CE. It was a long-lasting civilisation that lasted nearly a millennium to the early 9th century until a new group of "swift horsemen" from the north, the (Mranma) (Burmans) of the Nanzhao Kingdom entered the upper Irrawaddy valley through a series of raids.