Here's a solution when the neighborhood cats make your kid's sandbox their restroom: make a Pallet Sandbox With Lid! One of my friends at work has two young children who love playing in their plastic sandpit. The problem is that the neighborhood cats like to play in it too. I was asked to make a sandbox to match a planter I had previously made for them.
Here's how you can make your own Pallet Sandbox With Lid:
I assembled the sides using six pallet boards cut in half (approximately 60cm). I cut the legs to approximately 45cm and attached them into the corners. I made a square from some spare 2X4 lumber and attached it to the inside at the bottom of the box and used some scrap pallet boards to fill in the bottom.
I made the lid using five slightly wider pallet boards and some more scrap boards attached to the inside so that it sits inside the opening of the box to effectively lock it in place.
I built this in about two hours, and I then painted it with some Cuprinol weatherproof outdoor paint.