The angled 4x6 legs on our Mountain Series play sets not only provide solid stability, they offer additional options for entry and play options, too " wide, flat steps, cargo ladders, rock walls and more! Floor supports provide additional stability, which comes in handy if you get the available Sundeck or add a Loft over the Monkey Bars! The optional under-fort Tire Swivel Swing is a favorite for kids and parents.