“Promise we’ll have another fort at the next house?” the girls asked. It was 2010 and we were moving to fit our growing family. Two years before we’d built a play structure for them, adapting it mid-way through as, the then-toddler, Avery broke her leg and needed larger stairs. “Sure, we’ll build another one,” we said. The girls gave the fort a fond farewell and whispered that they hoped the next family would enjoy it. The new house had a deep wooded lot and we decided to build the structure into the ring of trees. It took a lot of tinkering and reconfiguring as we anchored 4x4s into pine trees. “It doesn’t have to be perfect. It just has to be safe.” The girls…