"The area is away from endangered tree species in our original playground site and is in parkland overlooking lakes," said a representative for the garden in Haywards Heath, West Sussex.
"This move protects the ecology of West Sussex while ensuring our botanically-rich garden brings pleasure to people for many years to come."
RHS Chelsea Flower Show award winner Julian Cochrayne designed the area with wooden elements including a raised walkway, balance beams and a zip line.
Andrewjohn Stephenson Clarke, chairman of directors for the garden, said: "Our key aims were to provide a safe and stimulating play area, allowing children to explore their creativity and enjoy adventurous exercise."
The play area has been named Harry's Playground after Stephenson Clarke's son.