Baiheliang (literally "White Crane Ridge")'s a rock outcropping in Fuling District, Chongqing, People's Republic of China, that parallels the flow of the Yangtze. In the past it served as an ancient device for measuring water levels of the Yangtze in China, the equivalent of a hydrometric station. The horizontal rock ledge 1.6 km long and ten to fifteen meters wide, lay submerged under water most of the year, showing its upper face above water only during the low-water season of winter and early… (More on Baiheliang)