More ideas from Franco
Backyard skatepark. I bet that I could stretch a design like this a little longer and taller and fit it into the basement of a house...

Everyone needs a mini ramp in the backyard :) parents, notice the kid isn't fat! Build these for your children, don't buy video games! The ramp is just big enough to have fun yet small enough where he's not going to get seriously hurt even if he does fall