SOCHI, Russia (AFP) - Smoothly run and sometimes dazzling, the Sochi Olympics fulfilled President Vladimir Putin's promise of a "spectacular event", even if doubts about the sustainability of the infrastructure and the political background were never fully banished.

To make his dream a reality, Mr Putin in half a decade turned largely untouched marshland south of Sochi into an Olympic park with six stadiums and the almost virgin mountains above into a world-class snow resort.

The price tag was more than US$50 billion (S$63.4 billion), making Sochi the most expensive Games in history, and the project bore the hallmark of the Russian strongman from even before the bid in 2007.

Despite International Olympic Committee (IOC) President Thomas Bach's call for political slogans not to be made on the "backs of athletes", politics was rarely far away amid alarm over Russia's rights record and the crisis in Ukraine.

But Russian officials boasted that the Sochi Winter Olympics had succeeded in exploding stereotypes about Mr Putin's Russia, saying the country showed an open face to the world and proved it could live up to its commitments.

"The ice of scepticism towards the new Russia has been broken," declared Deputy Prime Minister Dmitry Kozak. "Now you have seen that Russia can keep its word." The Games slogan "Hot. Cool. Yours." was ridiculed when it was unveiled but seemed more apt by the end, with spectators enjoying comfortable temperatures, the snow just about holding and the atmosphere improving all the time.

Many came to Sochi expecting oppressive and draconian security after Caucasus Islamist militants threatened attacks. But while thorough and widespread, the measures were rarely intrusive.

The idea of holding the Winter Olympics in a sub-tropical resort had seemed odd and temperatures even in the mountains became so high at one point that some cross country skiers donned shorts.

But Russia was helped by a heavy snowfall in January and intensive preparations meant there was never any shortage of the white stuff.

International Ski Federation Secretary General Sarah Lewis said the weather had been "challenging" but in the end the events had been "Olympic class".

She said the organisers had sensibly ensured there was a "strong, deep and compact snow base" that can cope with "a lot of problems".

When Mr Putin, in painfully accented English, presented the Sochi bid at a now famous 2007 IOC session in Guatemala, he gave his guarantee that the facilities would be finished on time despite the ambition of the project.

And finished on time they were. But only just, with media checking into their hotel rooms to find workers still hammering nails into the walls.

Quite whether Mr Putin's Russia transformed its image during the Games remains doubtful and one of the abiding images of these Olympics may be that of a vigilante Cossack laying into members of the Pussy Riot feminist group in Sochi city centre with a horse whip.

Thirty-three human rights groups, including Human Rights Watch and Amnesty International, wrote to Mr Bach saying the Olympics should not be held in countries with discriminatory laws, in a reference to Russia's anti-gay legislation.

Ecological activist Yevgeny Vitishko, who had raised alarm over the consequences for the environment of the Games, was ordered to serve a three-year jail sentence for vandalism, which his supporters said was a pretext for eliminating a critic.

"A cross has now basically been put over what was a unique ecological area," said his group, the Environmental Watch on North Caucasus.

Sochi Games chief Dmitry Chernyshenko insisted there would be "no white elephants" after the Games, with the mountain facilities set to be part of a top-class tourist resort and all the coastal stadiums to find a use.

Others remain to be convinced. Alfons Hoermann, head of the German Sports Confederation, said the Sochi Games had raised the standards in many respects but going forwards the toughest issue would be the "sustainability" of the venues.

He said the South Korean 2018 Winter Games host Pyeongchang would offer a middle way between the ambition of Sochi and hosting the Games in Europe.

"There is not going to be the extreme time pressure there," he said.