Multi-Level swing sets offer children of all ages excitement and adventure. When adding a Half Shack to a playset, you have a deck that is one foot lower than the main fort giving you a dual level swing set. When you add both a Half Shack and a Lookout Shack, this creates a Tri-Level swing set. The Half Shack is one foot lower than the main fort and the Lookout Shack is one foot taller than the main fort.