Performers celebrate at the end of the closing ceremony
The London Olympics lost its first medallist to a doping scandal on Monday as Belarus shot-putter Nadezhda Ostapchuk was stripped of gold a day after the Games closed in a blaze of music and colour.
Thousands of athletes began a mass exodus from London and turned their thoughts to Rio de Janeiro in 2016, as Britain basked in the adulation for a Games that electrified billions of viewers around the globe.
London's Heathrow Airport said it was expecting the busiest day of the Games on Monday with 6,000 athletes travelling through a special Games terminal and another 11,000 officials and media due to leave through normal channels.
Many would be leaving with little sleep after a glittering closing ceremony featuring The Who, the Spice Girls, George Michael and Brazilian football legend Pele entertaining a crowd of 80,000 at the Olympic Stadium.
But 31-year-old Ostapchuk waved goodbye not just to the Games but also to her women's shot put title after the International Olympic Committee said she had tested positive for the anabolic steroid metenolone.
Ostapchuk, the 2005 world champion, took a surprise gold medal with a throw of 21.36m, but urine samples provided the day before the competition and immediately after it both tested positive, the IOC said.
The gold medal will now go to Valerie Adams of New Zealand, with Russia's Yevgeniya Kolodko taking silver and Lijiao Gong of China bronze.
The news failed to dampen the mood in Britain though, with London Mayor Boris Johnson saying that for him and many other Londoners the Games had been "the most extraordinary event we can remember in our lifetimes".
Olympics chief Sebastian Coe, speaking at the same press conference as Johnson, said he hoped there would be a long-term boost for British sport.
"These British moments, those international moments that we've seen in those venues, will do more than anything else to inspire young people to take up sport," Coe said.
During two weeks of sporting spectacle record-breaking Jamaican sprinter Usain Bolt and US swimmer Michael Phelps lit up the Olympic Park in east London.
Heptathlete Jessica Ennis led an unexpectedly high number of British champions who kept fans' excitement at fever pitch.
The United States topped the medals table with 46 golds, eight ahead of China, while Britain had 29 -- their best since 1904. It was the first Games where every team had at least one female competitor.
The closing ceremony also saw the Olympic flag handed over to the mayor of Rio, a symbolic transfer which launches the four-year countdown to the 2016 Games.
Rio gave a taste of what to expect with a swinging samba section in a ceremony that included Pele and carnival-style dancers.
IOC President Jacques Rogge, speaking during the closing ceremony, praised the Games as "happy and glorious" -- a reference to the lyrics of Britain's national anthem "God Save the Queen".
After 16 full days of competition, 302 Olympic titles were handed out and 46 world records broken.
More than seven million fans came out to watch Olympic events, and Bolt's 200m win generated a staggering 80,000 tweets a minute.
Prime Minister David Cameron received congratulations from US President Barack Obama, who called him to praise the organisation of the Games and the performance of the British team.
Cameron said the Games had reflected the best of Britain's multi-cultural complexion, taking the example of Mo Farah, who won a rare 5,000m and 10,000m double.
"Over the past couple of weeks, we have looked in the mirror and we like what we have seen as a country," Cameron said.
Around 5,000 fans gathered in Leeds, northern England, to give a hero's welcome to three local medallists.
Triathlon winner Alistair Brownlee, his bronze-winning brother Jonathan and cycling road race silver medalist Lizzie Armitstead greeted Union Jack waving crowds before attending a reception in the city centre.
Farah came to Britain at age eight after spending his early years in Somalia and Djibouti.
Britain's newspapers on Monday reflected the country's newfound pride but also betrayed a tinge of sadness that the Games were over.
"Thanks, it's been a blast," said the Daily Telegraph over a picture of the giant Union Jack that covered the floor of the Olympic stadium during the closing ceremony, while the Guardian bade "Goodbye to the Glorious Games".