SOCHI, Russia — Now comes the hard part.

After Sunday night’s closing ceremony, Sochi must confront life after the Olympics and the impact of a building boom that, for a time, made it the world’s largest construction site. The area is now home to more than 40,000 hotel rooms, four ski resorts, dozens of restaurants and retailers, five sports arenas, one stadium, and enough roads and railways to handle 20,000 visitors an hour.

That made sense during the Games, but what will happen when fans and athletes leave? This question faces every Olympic city, but it seems acutely problematic in Sochi, experts say, in part because the scale of overbuilding vastly exceeds what occurred in Vancouver, London and elsewhere, and in part because the area will face competition from resort towns in other countries.

It also seems that few people in the upper echelons of the Russian government have given the future of Sochi much thought.

“I don’t think anyone is sure what to do with it,” said Sufian Zhemukhov, co-author of a coming book on the Sochi Games. “I say that because President Putin and Prime Minister Medvedev have changed the concept many times. First, it was going to become a kind of capital of southern Russia. Then they talked about dismantling the arenas and taking them north. A few months ago, Medvedev said they were going to open casinos there.”