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.
"Clean your kids toys in the dishwasher with vinegar! Use 1 - 2 c. (And recipe for spray to clean wooden toys and others that can't go in the dishwasher.) Via Lilac City Momma" great tip for the classroom toys