Five independent dredged islands, including a main island that connects to the rear land area by pavements, four ancillary islands located on both sides of the main island in embracing configuration. The islands are connected by a submarine tunnel to form a ring traffic network. The islands are protected by a semi-circular breakwater, which ensure the berthing stability of water area. The design concept of dredged islands originates from the abundant butterfly resources in Hainan Province. The outline and functions of each island corresponds to the shape and related habits of a butterfly species owned by Hainan Province.