"Sites such as Harappa continued to be inhabited and are still important cities today. . . . Late and post-Harappan settlements are known from surveys in the region of Cholistan, . . . the upper Ganga-Yamuna Doab,. . . and Gujarat. In the Indus Valley itself, post-Harappan settlement patterns are obscure, except for the important sites of Pirak. . . . This may be because the sites were along the newly-stabilized river systems and lie beneath modern villages and towns that flourish along the same rivers."