WHAT

Name: Adventure Playgrounds, Junk Playgrounds, Mud Parks, Play Parks, Loose Parts

While I don't totally agree with Christophe Haubursin's every detail in this video--it is a great introduction to adventure playgrounds. 

Tools: A key feature to many adventure playground. Hammers, nails, saws, shovels, paint

Ropes: trig functions, tension

Mud and Water: physics, plumbing, pressure