Tianshui lies along the route of the ancient Northern Silk Road at the Wei River, through which much of trade occurred between China and the west. Nearby are the Maijishan Grottoes filled with thousands of Buddhist sculptures, represented by figures as Sakyamuni and Avalokitesvara, produced in as early as the Wei Dynasty and as late as the Song Dynasty by Buddhist monks who first came here via the North Silk Road and, later on, by local Buddhists, for worship purposes. The Qin state, later to become the founding dynasty of the Chinese empire, grew out from this area, and the Qin name itself is believed to have originated, in part, from there Qin tombs have been excavated from Fangmatan near Tianshui, including one 2200 year old map of Guixian County. September, October, and November are the best months to visit Tianshui.