Shoebox lid & craft sticks- these are wide ones, and low temp glue gun. Endless fun and all you need is a shoe box lid and Popsicle sticks! Build a marble run or "Plinko" with all kinds of different creative designs via Frugal Fun For Boys
fun for summer camp Turn your backyard into your very own Inside Out playground. Inspired by Riley’s love of hockey, this game of outdoor field hockey uses items you already have in your home: pool noodles, balloons, and laundry baskets.
Carnival party hole in one putt putt homemade game - this could be cool but maybe a little longer to accomodate older kids as well. Could also be friendly for the Seniors as in its not requiring too much physical activity.