Several months ago, Wen Zhiguo, manager of a local hotel that caters to aging snowbirds, was forced to move to the outskirts of the city after the local government tore down his seaside facilities. Despite the change in location, Mr. Wen continues to run a brisk business renting out rooms to retirees who pay about $350 a month in exchange for simple accommodation and three meals a day.

On a recent afternoon, the lobby of Mr. Wen’s hotel began to stir as guests rose from their lunchtime naps. The choice of activities was plentiful — calligraphy, mah-jongg, cards and table tennis — and the faint scent of medicinal ointment infused the sunlit room.

A stately looking man with a snow-white coif sat quietly at a table playing a game of mah-jongg solitaire. A retired soldier in the People’s Liberation Army, Wang Xingeng, 89, remembered the first time he visited Sanya more than a half-century ago, just after the Communist Party’s 1949 takeover.

“Back then, the island was all shabby little huts, there were no buildings,” Mr. Wang said. “It was the poorest place I’d ever seen. It’s where they sent criminals.”

“I never thought I’d be back here,” he added, looking around pensively at his fellow snowbirds. “But now I’ve come full circle.”