The live-tree church in New Zealand built by Brian Cox is perhaps the most unique church in the world. The most impressive part is that it only took 4 years from start to finish.
After carefully choosing which trees to use he set about creating the steel frame which would form the basic structure of the church. His secret to the speed of the churches creation lies in the fact that he owns a company called Treelocations and using the specialised equipment available to him he was able to plant whole, living trees, speeding up the process of the church growing into its final form.
More information can be found at treechurch.co.nz.