A northern area of the Olympic Park will reopen to the public exactly a year after the Games' opening ceremony.
North Park, which will have waterways, playground and a 7,500 capacity venue, will open on 27 July 2013, the London Legacy Development Corporation said.
At Easter 2014 the southern part of the park, a 50-acre urban space called South Plaza, which includes the Orbit and Aquatics Centre, will open.
The Stratford site, east London, will fully reopen as a public space in 2014.
The North Park, which can be accessed through entrances in Hackney, Tower Hamlets, Waltham Forest and Eton Manor, will also include the Lee Valley Velo Park.
The entire Olympic Park will be renamed the Queen Elizabeth Olympic Park after undergoing an 18-month transformation following the Games.
There are plans to build up to 11,000 new homes on the site, three new schools and nurseries, health centres and community and faith spaces.
Andrew Altman, chief executive of the London Legacy Development Corporation, said: "The transformation will take the Park from an Olympic site, to a new piece of London that's owned and shaped by the community in and around it."
London Mayor Boris Johnson said: "Within a year of the close of the 2012 Games, the Park will be ready to welcome not only another major sporting event, but also the thousands of residents and workers who will reap the benefits of this brand new district of the capital.
"The Park will help drive the growth London needs to steer it out of recession."