The islands are situated in the South China Sea, to the south of the opening of the Pearl River estuary and Hong Kong. The archipelago includes several groups of islands. The western group, located south of the Pearl River estuary and Lantau Island, was formerly known to Europeans as the Ladrones, from the Spanish for "thieves". It comprises Greater Wanshan, Guishan, and Wai Dangling Islands and the Zhizhou, Sanmen, and Aizhou groups