The Tinker Crate line at Kiwico is for ages 9-16. This particular crate, the mechanical bird, could probably count as an engineering/art crate. This crate contains gears and paper/cardboard pieces to build your own bird that can flap its wings.
When I was a child I really enjoyed rocks. Whenever we would go to a mineral store or a national park I would buy a few shiny rocks for my collection. One of the things I always wanted was a rock tumbler to make my own rocks. When our second oldest son showed an interest in rocks we decided to get him a tumbler so he could make his own.