Daya Bay, an important bay in the South China Sea. Located between Red Bay and Dapeng Bay in eastern Guangdong Province. The total area is 650 square kilometers. The hills around the bay are composed of various metamorphic rocks, purple sandstone, tuff or granite from the Paleozoic and Mesozoic ages. The coast wheel porch is twisty and changeable, forming a hidden situation of the "big bay set small bay" in the near shore waters.