The Mound helps children experience different levels and terrains which assist in balancing skills, crawling, and physical fitness as well as makes for a great outdoor circle time story-time bench for your outdoor classroom. The Mound dramatically transforms your play area’s landscape. The Mound is made of low density polyethylene with threaded metal inserts for accepting bolts. Connection parts and covers are made from low fade natural rubber. The Mound is an optional piece on lower priced Snug manipulative play systems.