Sanya is the southernmost city on Hainan Island, and one of the four prefecture-level cities of Hainan Province, in Southeast China. The city is renowned for its tropical climate and has emerged as a popular tourist destination and has become known as "China's Florida", drawing many retirees from Northeast China during winter.  After seeing a massive influx of visitors in recent years that put great burden on the existing Phoenix Airport (built in 1994 with only one runway), Sanya is looking for a new aviation hub to cope with rising tourism.. Sanya’s new airport, the first airport in mainland China to be built on an artificial island through land reclamation in the sea, will be situated in Hongtang Bay Tourism Resort Zone, Tianya District. The project will involve a total investment of more than 100 billion yuan (~USD 16.3 billion), and the designed annual passenger throughput of the new airport will be 60 million. Scheduled to cover an area of 26 square kilometers on an artificial island in Hongtang Bay, the new airport will have four runways and three terminal buildings upon completion. It will be 5.18 times larger than the current Sanya Phoenix International Airport. Construction began in September 2016 and the airport was originally expected to be put into trial operation on 31 December 2020. Passenger throughput of the new airport is expected to reach 38 million by 2025 and 70 million by 2045. The new airport is expected to be an international transportation hub and a gateway to Southeast Asia and the South China Sea. In addition to the airport, other supporting facilities will be built on the island including an aviation economic zone with an airport and seaport operation area, an international aviation CBD, and an industrial zone in support of the airport. The new airport project is backed largely by HNA Group Co., Ltd., and it is part of China’s “One Belt, One Road” plan (The Belt and Road Initiative).