1. Prepare the ground by digging four holes, one for each swing set leg. The holes should each be at least 5 inches deep and 10 to 12 inches wide.
2. The bottom of each hole should be covered with a stone or brick. Otherwise, the legs of the swing set will sink deeper into the ground.
3. Attach the swing set legs to the holes. Make sure each hole is completely filled with concrete. Allow it to cure and dry. Five to seven days is usually enough.
4. Around the swing set, you should provide at least six feet of shock-absorbing material, such as wood chips or sand. The material should be six inches thick. Provide more material around the front and back of a swing to prevent children from falling or jumping off.