All visitors to the West Lake are impressed by the Bai Causeway and the Su Causeway spanning the lake, which are some of the main artificial elements of the lake, two causeways and three islands. They were built by famous poet Bai Juyi of the Tang dynasty and famous poet Su Shi of the Song dynasty, respectively, when they served as Magistrate of Hangzhou.

Both Bai Juyi and Su Shi meritoriously built water conservancy projects in Hangzhou because of the specific geographical conditions of Hangzhou, and more importantly, of their deep understanding of the local people's livelihood and their courage and willingness to address it. The Bai Causeway and the Su Causeway are the results of the dredging of the West Lake in ancient China, and are monuments to scholar-bureaucrats who let others be benefited.