Giuliano Mauri's "Cattedrale Vegetale" is arguably the most impressive piece of ‘natural architecture’ on Earth. Located at the foot of Mount Arera on the outskirts of Bergamo in the North of Italy, this living sculpture consists of a cage made from wooden poles, assembled to represent the columns of a church nave. Inside this cage, Mauri planted eighty hornbeam saplings. The artist claims that, in fifteen years time, the supporting structure will have gradually decayed and the hornbeams will have grown to form a completely organic "cathedral".
Mauri laid the groundwork for the Tree Cathedral in late 2001. Following his death in 2009 the Cathedral was finally completed in 2010 and it will remain as a living memorial to Mauri’s work.
The Cathedral comprises 42 columns forming a basilica of five aisles. The project makes use of 1,800 spruce trunks and 600 chestnut tree branches which are bound together by over 6,000 meters of hazelnut twigs, utilizing local traditional methods of intertwining and weaving. As the beeches grow they will form a natural roof across the Cathedral. The Cathedral takes up 650 square meters and took months to construct. It is more than 90 feet long, nearly 80 feet wide, and ranges in height from about 16 feet to nearly 70 feet.