This was, according to the then Mayor of London, a unique opportunity to pump billions of pounds into a neglected, poverty-stricken corner of East London, for the benefit of local people.
Four years on, a transformation is undeniably underway.
But regeneration has not delivered for everyone.
House prices and rents in the surrounding areas have soared, forcing many local people to leave, and contributing to a sharp rise in homelessness.
Long after the cameras have moved on, London's legacy remains bitterly contested.
Cranes dominate the park skyline, as construction kicks into a higher gear.
Around 8,000 homes will be built on the site over the next 15 years, and a further 16,000 around the park over the same period, according to the London Legacy Development Corporation (LLDC), the government body charged with managing the transition.
The park will also see a new commercial district, the £2.4 billion ($3.1 billion) International Quarter
, which will provide office space and business facilities for 25,000 workers. A Cultural and Education District
will host museums and two new university campuses.
Peter Tudor, director of visitor services at the LLDC, estimates that around 40,000 jobs will be created on-site, from gardeners to building contractors.
A further priority is to provide services to ensure quality of life for the expanding population.
"Our focus is on sustainability and making sure there are provisions for things like doctor surgeries and education," says Tudor. "We are making sure it's not just houses and offices, that we are providing the infrastructure so people can really live here."
The transformation also extends to the surrounding area. Newham borough is now home to the largest mall in Europe
, and local transport links have received major upgrades -- with the £27 billion Crossrail 2
project still to come.
Property values in this area have climbed rapidly due to the surge of development.
In Newham, which remains one of London's poorest boroughs, the average house price has increased by 43%
But there are concerns that higher values have worked against local people.
The original bid promised 50% affordable housing in the park, but this has since been revised down to 31%. New estates outside the park have a target of providing one-third affordable housing, but the LLDC has little power to enforce this on private developers.
The definition of "affordable" is highly contentious, too, set at 80% of market rates.
One affordable home in the park's Chobham Manor estate was recently available for £470,000 ($614,000), far beyond the reach for most people in Newham, where the average income
is under £29,000 a year ($38,000).
"We have lots of housing being built and planned, but it's at odds with the needs of the area," says Dr. Penny Bernstock, a specialist in urban regeneration at the University of East London, and author of "Olympic Housing: A Critical Review of London 2012's Legacy
Bernstock found that the number of homeless households in Newham increased by 122% between 2012 and 2015, with many more placed in temporary accommodation.
There has also been a sharp rise in Olympic borough councils housing residents outside the borough, and even outside London
Still, the LLDC is pleased to have avoided "white elephants," unlike previous hosts such as Athens in 2004, where an $11 billion investment left rusting stadia
, which became powerful symbols of waste during Greece's debt crisis.
But London's approach has also been controversial. Premier League soccer club West Ham United acquired the £700 million ($914 million) Olympic stadium for just £15 million ($19.5 million), plus £2.5 million ($3.3 million) a year in rent.
Bernstock questions whether world-class sporting facilities truly serve the needs of the area.
"People can learn from London to think more clearly if they want long-term benefits to the community," she says. "A park full of venues is not necessarily the best way to regenerate an area. It almost acts as a block."
But Dr. John Gold, who analyzed the effects of hosting the Olympics for his book
"Olympic Cities City Agendas, Planning, and the World's Games," suggests the venues could bring longer term benefits.
"It is likely that the presence of the stadia will help to improve the area's image and give investors confidence to back projects in the area," he says. "It is likely that further developments will follow."
The idea that the Olympics leave a positive social legacy on a host city is a relatively recent one.
"After (post-war) austerity, the Games started to get larger through the 1950s and 1960s, with more sports, stadia, participants and support needs," says Gold.
"In the late 1960s, 'gigantism' became a concern as the Olympics became more of a burden on host cities, particularly after Montreal 1976 which bankrupted the city for 30 years."
The number of bidding cities declined after the debacle of Montreal
, and the International Olympic Committee (IOC) responded with a new vision. The 1980 Olympic report repeatedly stressed the word "legacy" and the concept gained traction.
Barcelona 1992 is frequently cited as the most positive example of Olympic legacy, where a relatively run-down city was transformed with two new highways, new neighborhoods and the renovation of what is now a world-famous seafront.
"Cities have different approaches but one of the basic distinctions is between looking at the whole city (like Barcelona) or just having a site like Stratford in London," says Dr. Sue Brownill of the Department of Planning at Oxford Brookes University. "The clever cities use the Olympics to implement a strategy they were going to do anyway."
Few host cities have land available for a vast Olympic Park, and creating space can be problematic.
"You can either take land that nobody wants," says Gold. "Or you have to evict people."
Evictions have become a disturbing Olympic tradition. More than two million people
were displaced between Seoul 1988 and London 2012, according to the Center on Housing Rights and Evictions. The trend has continued in Rio with tens of thousands forced out, in often-brutal favela clearances
The displacements, combined with the vast public expenditure, have fostered widespread Olympic skepticism. Anti-Olympic protests were held in London
, followed by larger demonstrations in Rio, where police used tear gas
to disperse angry crowds.
The growing Olympic backlash has seen Stockholm, Munich, and St. Moritz dropping their bids to host the 2022 Winter Games, the latter two cities after a public vote.
Boston and Hamburg have pulled out of the race for the 2024 Games.
"The IOC has a real problem, unless they can find more hosts in totalitarian states," says Brownill. "They may not be able to stage them anywhere else."
A new model
The IOC is aware of the need to reduce the burden on host cities, says Emilio Fernández Peña, Director of the Olympic Studies Centre at the Autonomous University of Barcelona, and a consultant of the IOC.
"The importance of creating a more sustainable Olympic Games is clearly a big issue -- it is one of the key concepts of the IOC's Agenda 2020
," says Peña. "The Olympics must be more sustainable and demonstrate they are useful for society in general."
An alternative approach would be to abandon the idea of using the Olympics to regenerate cities, and instead stage them in handful of megacities that already possess the necessary infrastructure.
"My forecast is it will only be the big capital cities that host the Games in future," says Gold. "They will be repeated in cities like London and Los Angeles."