South Reef

South Reef ; Nam Reef ; Mandarin, is a reef on the southern part of the North Danger Reef of the Spratly Islands in the South China Sea. The reef has been occupied by Vietnam since 1988. It is also claimed by China, the Philippines, Vietnam, and Taiwan.
On the coral reef is a floating architectural complex called Nam Island, built in 1988, which serves as a military base for the Vietnamese Navy. The geographical coordinates inscribed on the sovereignty marker are 11°30′0″N 114°21′0″E. Soldiers stationed here collect rainwater for livestock and vegetable cultivation. In 2019, a multi-purpose cultural center was inaugurated and put into use on Nam Rock Island.
In October 2023, Vietnam began dredging and reclaiming Nam Island into an artificial island. As of March 2025, the island has been reclaimed to an area of approximately 60 hectares, with a length of approximately 1.9 kilometers and a harbor spanning approximately 40 hectares.