Easy (Pirate) Cork Boats - these little cork boats are super quick to make (takes minutes) and float REALLY well. Make them using craft foam for sails and you can have hours of water play in the garden. A great pirate craft for Summer.
A Dry river bed instead of a traditional sand pit. Large and smaller river rock lining a sand river with tree stumps, ferns and toys. This is a home daycare that has a lot of natural play elements in their backyard play environment.
DIY Sand and Rock Box by FSPDT. Gdjk -> made this with toilet rolls (aka tunnels) and moon sand instead of play sand. My son loved playing with it. The moon sand cleans up nicely indoors but play sand will be easier to play with when using the small cars.