Spring to Su Causeway is generally called Sugong Causeway, ranking first in ten scenic spots of the West Lake. It is a boulevard running though north and south scenic spots of the West Lake, starting from Nanping Mountain in south to Xixialing in north, 3 km long and 36 meters wide in average. Su Shi, magistrate of Hangzhou Prefecture of the Song Dynasty, carried out the work of dredging the West Lake. The sludges from the lake, mixed with grass, were used to build causeway, the causeway was then lined with willows, peach trees, flowers and grass on both sides. Besides, six stone arch bridges were built on the causeway.