This has got to be one of the coolest structures ever! The Redwoods Treehouse was originally created as a marketing campaign for Yellow (New Zealand's version of the Yellow Pages) in 2008. The idea was to create this treehouse using only sources from Yellow. The treehouse later became a venue for corporate functions and events. Who wants to go to New Zealand for company team building fun?!?
(photos from Redwoods Treehouse website, weburbanist and nzwood)