JAG Gymnastics, Andover

Jag Gymnastics may have a competitive team, but the gym was clearly built for fun, too. For instance, it's outfitted with a pint-sized zip line that delivers kids into a foam-filled pit, and it frequently hosts Parents' Night Out, which entertains kids with games and pizza.

And with its traditional vaults, trampolines, and ropes, it's the perfect spot for learning the ropes of tumbling and cheer jumps. The classes range from parent-and-me classes for 18-month-olds to advanced tumbling classes. The latter, like most of the parent-free classes, emphasizes safety, correct technique, and cool flips such as back saltos and back handsprings.