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.
10 lbs) ~ free or nearly free, if you have it cups corn starch (approx. 1 cup + 3 tablespoons) teaspoon dish soap (e. Dawn Dishwashing Liquid) water (about 1 cup) optional: 1 teaspoon Tea Tree Oil (for antibacterial properties)