Dadonghai
China's only tropical beach — exile island turned Special Economic Zone, now a separate customs zone from mainland China with 174 investing countries and $14.9B exports, tourism generating 60%+ of provincial GDP.
China has 1.4 billion people and one tropical coastline — and Dadonghai is the crescent-shaped bay where that monopoly first became an industry. Sheltered by hills on three sides at the southern tip of Hainan Island, this beach district sits 4 kilometers from Sanya's center and was the first scenic area developed for tourism on what had been China's exile island for two thousand years. Every dynasty banished dissidents to Hainan; as late as the 1950s, indigenous Li people lived in pre-modern conditions. The island's transformation from political punishment to economic prize began in 1988, when Hainan separated from Guangdong Province to become China's newest province and largest Special Economic Zone.
Dadonghai's geographic monopoly drives its economics. There is no alternative domestic tropical beach destination for 1.4 billion Chinese consumers. Tourism generates over 60% of Hainan's GDP — the inverse of most Chinese provinces, where manufacturing dominates — making the island structurally more similar to a Caribbean economy than a Chinese industrial zone. Sanya's GDP exceeded 100 billion yuan (approximately $14 billion) in 2024, and Hainan welcomed 97.2 million visitors spending 204 billion yuan ($28.9 billion) that year. Dadonghai itself covers just 19.49 hectares of land and 26 hectares of sea, yet holds China's second-highest tourism rating (4A scenic spot).
The phase transition accelerated in December 2025 when Hainan officially became a separate customs zone from mainland China — tariffs eliminated on most imports, creating China's most ambitious free-trade experiment. Countries investing in Hainan surged from 43 in 2018 to 174 by 2024; nearly 10,000 foreign-invested enterprises registered. Exports nearly tripled from $5.1 billion to $14.9 billion between 2021 and 2024. The island follows classic island biogeography: when barriers drop between an isolated ecosystem and a continental species pool, colonization accelerates exponentially.
Dadonghai's trajectory points toward a fundamental test: whether a tourism beach can serve as the gateway for China's largest opening-up experiment, or whether the free-trade port will outgrow its resort-town origins.