Any parent understands the cyclone effect of small children and toys.
Within minutes, that tidy playroom you spend hours organizing can look like a Category 5 just blew through. It's about the size of a large coffee table. Grass, ponds and roads can be painted on the surface, and the around the edge there's a lip, so all the small pieces don't end up on the floor. With a project like this, two important considerations are cost and time. I wanted to build it for substantially less than it would cost to buy, and I didn't want it to take forever.