There was lots of wood left over when dad dismantled the sofa. We propped one #board on a stone and rolled marbles down it.
This gave us the idea to make a track around the trunk of a big white pine. We took a hammer & nails & nailed some of the narrow boards to the tree, angling them toward the trunk to keep the marble from falling off. Around and around we went in spirals--we climbed high to make the track long--& when we let our marbles roll, it was fantastic.