Poll: Best fun thing to do with best friend when you are out of money and are limited?

My Best friend and I are doing a spring break thing together and I wanted some ideas of things to do. We probally won't have much money, maybe 20 bucks, and we can't go super far out of the neighborhood, and my mom won't want to drive us places. We already tried to make a tire swing, stupid kids cut it down, we have gone wagon sledding down a hill, so what did you do for fun when you where kids?