Poyang Lake consists of a big lake surrounded by smaller lakes. In the summer, the flooding of the Yangtze River fills the lakes, which empty in the fall to reveal vast areas of shallow waters and muddy banks, producing an ideal habitat for cranes, ducks and geese. To watch the many species of birds on Lake Poyang, one can take a boat from Nanchang to Wucheng, Yongxiu County, on the north shore of Lake Poyang, where a migratory bird sanctuary is located. The journey starts very early in the morning (check the departure time locally), takes two hours and costs 30 yuan. Cygnets, wild geese, storks and widgeons (a marshland duck) can be seen near Sha (Sand) Lake. The daily return boat to Nanchang departs at 2:30 p.m.