Down the hatch.

This is my nephew. He has a younger sister and brother and they have the coolest decking in their back garden. This section has a hatch which drops down to reveal the 'escape route' to the lower lawn. Another section of the decking lifts up to reveal a kid's sand pit. At the back of the house is a couple of water butts which collect rainwater - when you turn the tap on at the bottom it runs down through a hole in the decking and runs into the sand pit. The kids love it, I love it!

There's even a little circular hole for the clothes dryer - not that cool, but very practical!

Oh and there's a swing underneath the edge of the decking, just next to the ladder. Now if that was attached to the clothes dryer?

Genius