1138 (10")Ikos. Category 05: Tree Houses and Pole Houses Daniel Voelker & Hagen Hoffman: Germany Supported on a 10-cylinder hydraulic system, the Ikos can climb up every branchless tree trunk with a minimum diameter of 30cm. The Ikos follows the model of an icosahedron, made of 90 single bamboo bars connected to form 12 pentagons and 20 hexagons.
