Use an old tire to create a small backyard pond. My kids, 3 sons, have been helping with yard work and planting. They keep asking for a pond. I think this is a great DIY project to do outside with them. Looks simple.
DIY - Homemade Gabion wall ie rocks encased in wire baskets and used as a retaining wall - creates a dramatic feature in a garden. No directions on link. Nice someone figured out how to landscape with river rock. I swear they grow!