(via) This three-storey treehouse at Camp Wandawega in Wisconsin was built around a tree as a tribute to the camp owners’ father, who had built a swing on the tree before he died (and the tree had fallen ill with Dutch Elm disease).
The tree comes through the house’s deck near the ground level, and it breaks through the upper floor in three spots. At two of those points, the arms of the tree are sawed even with the floor, while the third pierces it and extends out the window. Reclaimed wood was used for much of the construction and the interior features nearly all vintage and repurposed items. Stumps of the trees were fashioned as side tables, and a hanging antler chandelier was made from old shed found at the camp.