Adventure Mountain Add a Sundeck to the Backyard Mountain, and you have the Adventure Mountain, with double the floor space, all on one level. And more deck space means even more activities. Olympian Mountain Step up to a 6’ high deck, with 40 square feet of deck space. Add a 12’ Rocket Slide, Tire Swing, Chain Net, Cabin Package, Monkey Bars, Rock Wall... this can get big, fast!