The three sand islands are Spratly Islands, the Zhongsha Islands and Paracel Islands. Among them, Spratly Islands is the most southern island in the South China Sea, and the Zhongsha Islands and Paracel Islands are among the four archipelago of the South China Sea Islands.
Spratly Islands, the Zhongsha Islands and Paracel Islands are known as the three Sand Islands, of which Spratly Islands is located in the South China Sea, and is the South most archipelago in the South China Sea. It was also called Wanli Stone pond and Wanli long dike in ancient times.
The Zhongsha Islands are one of the four archipelago in the South China Sea Islands, and it is in the central part of the South China Sea. The Zhongsha Islands are rich in biological resources, and its ecological group mainly includes dinoflagellate, diatoms, golden algae and cyanobacteria.
Paracel Islands is also one of the four archipelago in China's South China Sea Islands. It is the largest land area in the South China Sea. It has 22 islands, seven sandbars and eight atolls.