Build a structure where the kids would never want to come in! Combo Playhouse, Covered Play Structure and Sand Pit/Outdoor Toy Storage. Swings could be added. Built by Cubby Kraft, photo features Sandalwood Lodge Cubby House. Link leads to 50+ playhouse/structure examples.
Drill holes into your fence and replace them with marbles. 32 other backyard ideas.
outdoor fire place... I would love that!
Awesome water barrel
DIY Hanging Pallet Bed - Love This!