My parents let us tinker. I helped my dad with power tools. I carried and moved around bricks with bare hands and bare feet, and made my own little pathway in the yard. I dug with sticks in dirt, climbed trees, sat on the roof, picked up bugs, caught lizards, ran around, played with fire, baited my own hook, and caught my own fish. Sure, sometimes we hurt ourselves, and yep, I have a few scars from my childhood, but I learned and explored and discovered my independence more than the people my age who have no scars.
Tinkering = creativity and learning. Let your kids be dangerous.