Walk into this warehouse and you'll find kids of all ages and sizes doing flips, somersaults, and handstands and having their way with trampolines, balance beams, uneven bars, and rings. Join in; swing on the trapeze and drop into the "pit": a large man-made crater filled with big chunks of soft foam. This fantasyland for kids and adults is not the cleanest or best-organized place, we admit, but who cares when you can run, jump, and do multiple, one-handed cartwheels on surfaces that are safe, spongy, and resilient? Co-ed toddler classes are held six days a week; other classes are aimed at older kids, teens, and adults. If there's a clown inside you waiting to get out (in which case: eek!), check out the circus-tricks and juggling courses. Work scholarships are available for those who can't afford the monthly fees.