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.
The children in art class experience what it's like to draw with their feet and mouths (and elbows! This is not only a fun, action art experience, but it gives them a new appreciation and gratefulness for their hands.