This is such a simple idea, but one which had the kids really really excited (especially the 3 year old).
The concept is really pretty simple. Choose a load of toys that you don’t mind getting wet, and possibly damaged (old McDonalds toys etc are good for this). Put them in a Tupperware box, or even thread them inside balloons, then fill with water and pop in the freezer. That is all the preparation that you need.
The next morning, take the frozen toys into the garden, and supply a range of tools. The kids then have to excavate their toys out of the ice.
I can’t tell you how exciting the kids found this, they blooming loved it! In fact, they loved it so much that we were asked to do it again the next day!
My only warning would be… watch out for casualties! Definitely don’t freeze toys which are well loved. Most toys survived unscathed, but you just can’t tell which ones will get broken in the excitement.