In ground trampoline
Convertible circular area in the garden perhaps? Sink a kiddies paddling pool into the pit (easy to clean!) or sink a trampoline in there? Or somehow raise the area and form it into a fire pit. If it's possible to choose out of the 3, then it's a great convertible area to suit the weather and time of day!
The real ‘pièce de resistance’ is the concealed trampoline which is underneath the artificial lawn. It has a bespoke lid, exclusively designed by Floral and Hardy, means that it can easily be lifted and secured for children to play, and closed again when not in use, to seamlessly become part of the lawn once more.