Central London Reef

Central London Reef ; Trường Sa Đông Island ; Mandarin, is a reef on the central part of the London Reefs of the Spratly Islands in the South China Sea. The reef has been occupied by Vietnam since 1978. It is also claimed by the Philippines, Vietnam, and Taiwan (ROC).
The coral reef where Truong Sa Dong Island is located is a shallow reef when the tide is at its lowest. On the western side of the coral reef, there is also a small sandbar. The surface of the coral reef is uneven, so the varying depths can be dangerous for ships entering and exiting. The coral reef has an area of approximately 1 km2.
Trường Sa Đông Island is situated along the northeast-southwest axis in the northeast part of the coral reef. According to AMTI, the natural land area of the island is approximately 0.88 hectares, and after land reclamation, the above-water land area of the island was approximately 2.55 hectares as of 2016, with a length of approximately 250 meters and a width of approximately 120 meters.
Since late September 2023, Vietnam has been conducting land reclamation to expand Truong Sa Dong Island. As of March 2025, the island's area spans approximately 27 hectares, with a harbor covering about 16 hectares.