Climb a 10m tower, hang off the top, your toes just dangling beneath you and let go! Its got a 4m free-fall before the slide catches you and you whiz to the bottom.
If you're not comfortable with that then your classmates can just hoist you as high as you feel comfortable. The Giant Slide is a great activity to develop confidence at heights and is a great challenge by choice activity. All students wear overalls, gloves and head gear.