Alongside venues for sport and the arts, London's newest park features interactive water fountains and an adventure playground.
Visitors can go up the 375ft-high (114.5m) ArcelorMittal Orbit tower.
It is the biggest park to be opened in London for a century.
New homesIt is hoped the attraction will revitalise the neighbourhood and bring tourists to the area.
Take a tour of the new Queen Elizabeth Olympic ParkVisiting the park is free, although there will be charges for some of the attractions.
More than 10,000 new households are planned for the site by 2030.
Current attractions also include the Aquatics Centre and VeloPark, and future ventures are planned with the Victoria and Albert Museum (V&A) and University College London (UCL).
The development has been led by the London Legacy Development Corporation.
'Astonishing place'Mark Camley, the corporation's executive director of park operations, said most of the activities taking place over the opening weekend would be free of charge.
He told BBC Radio 5 live: "We have set out to create a new heart for east London."
The newly-landscaped southern section of the east London park reopened on Saturday Children can play in interactive fountains around the ArcelorMittal Orbit tower The park has been reopened to the public 18 months after the end of the London Paralympics An acrobat hangs from the tower. Organisers say the park will create "a new heart for east London"The opening comes after Prince Harry and London Mayor Boris Johnson paid a visit to the site on Friday.
The prince said the park was better than he expected, while Mr Johnson said: "It's far more beautiful than I possibly thought it could be.
"This is going to be a quite astonishing place to come and bring your family."
Will you be going to the Queen Elizabeth Park today? We'd like to see your pictures of the park.Send your pictures to yourpics@bbc.co.uk or text them to 61124. If you have a large file you can upload here.
Read the terms and conditions.