Sand Cay (10°23′N114°29′E), also known as Son Ca Island (Tagalog: Bailan; Chinese: 敦谦沙洲; pinyin: Dunqian Shazhou; Vietnamese: đảo Sơn Ca) is a cay in the Tizard Bank of the Spratly Islands in the South China Sea. With an area of 7 hectares (17 acres), it is the ninth largest, and the fourth largest Vietnamese-occupied, of the Spratly Islands. The island has been occupied by Vietnam since 1974, (first by the Republic of Vietnam, then by the Socialist Republic of Vietnam after 1975).