This is SUCH a simple activity to set up for the kids, but since it’s so different than what they’re used to it grabs (and more importantly keeps!) their attention for a long time!
All you need to do is take some of your Lego boards and tape them to either the wall or a window (be mindful of the paint if they’re going on a wall) and then just let the kids build OUT instead of UP!
I set this up for the boys this weekend and even though they were using the exact same Legos that they always have, playing with them on the window kept them quietly playing and creating for over an hour!