K'nex Beginner Builds Building Set Construction Toy Kids Gift

What you're getting

You've got 125 colourful pieces that snap together to make 3D models—think monster trucks, spaceships, that sort of thing. Comes with 10 different model ideas to get them started, though once they've got the hang of it they can design their own.

The colour-coded rods and connectors make the step-by-step instructions straightforward enough, so they'll actually be able to follow them without you having to decipher it all first. It's the kind of thing that keeps them occupied on a rainy afternoon and genuinely teaches them something about how things fit together.