PicassoTiles Engineering Construction Set with Toy Power Drill - 250 Pieces

My 6-year-old sat at the table for almost two hours building a crane with these, which never happens. The plates snap together tightly and hold up even after he takes it apart and rebuilds it three different ways. Wish I'd bought this set sooner.

The working drill is what sold me — my daughter actually screws the pieces together herself instead of just snapping blocks. She's built a little crane and a bridge so far, and the pieces hold tight even after she takes them apart.

The 250 pieces kept my son busy for a solid two hours on a rainy afternoon, and he figured out how to attach the wheels without any help from me. The drill is the star though, he loves swapping bits to tighten every bolt himself.