I've often thought the Goodyear Airdock in Akron, would be good for something like this. It nearly as long, about half as wide and a bit over half as tall. Would still make for a nice indoor amusement park combined with shopping and other activities... if Lockheed, Loral or whomever owns the property and the surrounding buildings now wasn't there anyhow (silly thing is I work right next to it and I can't recall who ones it right now).