The New South Wales' Government is spending more than $7 million on a "mega playground" for the children of western Sydney.

The playground will be build across three hectares of riverfront land within the grounds of Sydney Olympic Park.

Announcing details of the park today, Premier Kristina Keneally says it will become a major drawcard for the region, with entertainment for kids of all ages.

"A mega swing area, a double flying fox, a scramble wall, a sandpit, a tree house with rope ladders and bridges and tunnels," she said.

"Everything here to set a child's heart alight, to set the smile on their face and to get them out and about, active and moving."