The oldest surviving manuscript star chart was the Dunhuang Star Chart, dated to the Tang dynasty (618–907) and discovered in the Mogao Caves of Dunhuang in Gansu, Western China along the Silk Road. This is a scroll 210 cm in length and 24.4 cm wide showing the sky between declinations 40° south to 40° north in twelve panels, plus a thirteenth panel showing the northern circumpolar sky. A total of 1,345 stars are drawn, grouped into 257 asterisms. The date of this chart is uncertain, but is estimated as 705–10 AD.