Solitary Island is connected to downtown Hangzhou by Baidi, one of the two great man-made causeways that divide West Lake into three parts. These two causeways are the finest stretches to walk on West Lake. Both are scenic and serene. The Bai Causeway is named after a Tang Dynasty poet, Bai Juyi, who was the great poet in the Tang Dynasty (618-907A.D). He once supervised over some constructions of the West Lake (Bai Causeway included) after serving as the local governor of Hangzhou from 822 to 824A.D. Composed of silt dredged from the lake, the Bai Causeway is a 0.62 mile long embankment with plum trees and weeping willows planted on both sides, which makes it especially nice scenery in the spring. This causeway travels northward and starts at the "broken bridge", traveling through the "golden ribbon bridge" and ends at the "autumn moon on a calm lake" to make it a very interesting journey.