Grand Adventure Play Systems offers you a maintenance-free option in backyard swing sets. The ultimate in safety, Grand Adventure Play Systems are an investment in quality...and FUN!Grand Adventure Play Systems are made with ProWood Micro* yellow pine that is then fitted with a vinyl sleeve for added strength, safety and durability. Maintenance-free, our play systems also incorporate poly lumber - the same material used in maintenance-free decks. The poly lumber is actually made from recycled milk jugs and other plastics. We're proud of the fact that our systems are not only safe, they're environmentally friendly too!