Animals - Everything from microscopic protozoa, through snails and spiders to the more complex vertebrates such as birds, lizards, dogs and cats. Plants - Again, from the simplest microscopic bacteria, to the mosses, fungi and ferns, shrubs and trees. Earth - Stones, rocks, sand and soil, etc. are all commonly used in play. Man made objects - Toys and playground equipment are the most obvious man made play objects, however such things as buildings, walls, pavements, fences, etc. Too often, however, instead of exploiting the play potential of these things, we discourage or even ban play around them.
Brick walls can become rebound walls.
Fences and walls can be used for murals, or a lean-to cubby. When catering for kids you have the job of selecting and combining these components to achieve an appropriate environment which will enhance play in the area being designed. Toddlers enjoy exploring and learning about their physical surroundings. It is important to include variety in textures, smells and surfacings. Older children interact more with each other, so the backyard needs to be designed to allow them to play with each other rather than with things.