Even before the construction of Frolic's Castle, Memorial City Mall sported the best indoor playgrounds in the city. Now it's so good it's hard to believe it's free. It features a massive, multi-story castle set among an equally huge fairy-tale forest, and kids can run, jump, climb and play for hours in the cool air of the mall. Plus, the playground is gated and monitored by a security guard so that you don't have to worry about your munchkins running out of your sight as they dart among giants and dragons. The only downside is that Frolic's Castle is open only during mall hours, so be aware if you're trying to get in an early Sunday morning play session that the gate will likely be locked.