Many of us fall in love with tree houses as children but leave them behind when we grow up. These days, though, more and more adults are rediscovering the joys of arboreal hideaways. Tree houses are in -- and branching out. They're the subject of best-selling books, workshops and exhibitions. Some people enjoy their lofty living rooms as weekend retreats; others use them as offices, or even as full-time residences. They serve as blinds for watching wildlife, religious retreats, dormitories and overnight resort suites.
Tree houses have a long history. From the Middle Ages on, tree arbors were popular in Europe. During the Italian Renaissance, the Medicis built a marble extravaganza in a tree. A town just west of Paris became famous in the mid-19th century for its arboreal restaurants. But the most famous tree houses of all time existed only in the imagination, including the one that was home to author Johann David Wyss' shipwrecked clan, the Swiss Family Robinson.
These days another author, Peter Nelson, has assumed the mantle of "Mr. Tree House." His book, Treehouses: The Art and Craft of Living Out on a Limb (Houghton Mifflin), has sold more than 50,000 copies since it was published three years ago. In October, Nelson and a host of other enthusiasts will gather at the Treesort in Takilma, Oregon, for the first meeting of the World Treehouse Association.