Southwest Cay, part of North Danger Reef, is one of the Spratly Islands contested by Viet Nam, China, Taiwan, Philippines and Malaysia. It was a breeding place for birds in 1963, when it was covered with trees and guano. Export of guano was once carried out on a considerable scale. It also has the highest point of Spratly Islands, unnamed location 4 metres above the sea level. Vietnam erected its first
lighthouse in the Spratlys here in October 1993 and there is also mention of airstrip but it seems not to exist. Otherwise the tiny island seems to be completely build up. This island has specifically been claimed by Philippines, in fact some
sources state that facilities on island are Filipino but
GlobalSecurity.org and many other sources says it's Vietnamese controlled. It is called Song To Tay in Vietnamese.