Thitu Island

Thitu Island, also known as Pag-asa Island (Filipino: Pulo ng Pag-asa, lit. 'Island of Hope'); Đảo Thị Tứ (Vietnamese: Đảo Thị Tứ); Zhongye Dao (Chinese: 中业岛/中業島; pinyin: Zhōngyè Dǎo), having an area of 37.2 hectares (92 acres), it is the second largest of the naturally occurring islands in Spratly Islands. It lies about 500 kilometers (310 mi) west of Puerto Princesa. Its neighbors are the North Danger Reef to the north, Subi Reef to the southwest, and the Loaita and Tizard Banks to the south. As the poblacion (administrative center) of the Kalayaan municipality of Palawan province in the Philippines, it also administers nearly a dozen other islets, cays and reefs in the Spratly Islands. The island is 270 nautical miles west from Palawan, Philippines.

In 1971 following a storm on the island the island was seized by the Philippines from the Republic of China (Taiwan). it is administered by the Philippines as a part of the Kalayaan municipality of Palawan Province.

In May 2020, the island's new sheltered port, and harbor were built, as well as a beaching ramp at the tip of the airstrip. In early 2023, the concreting of the runway was completed. Civilian infrastructure on the island include the airstrip, a lighthouse, a 5-bed lying-in clinic, a communication tower powered by Smart, and a small integrated elementary and high school.

The island is the largest of the Philippine-administered islands in Spratly Islands. While most of the occupants of the structures in the Spratly Islands are military personnel or temporary tourists, the island is the only one with a permanent civilian settlement. China (PRC), Taiwan (ROC) and Vietnam also claim the island.