The latest addition to Cornwall's Eden project opened this week. The £15M structure's timber framed roof was designed by engineers SKM Antony Hunt and Buro Happold with architect Nicholas Grimshaw. Curved timber components resemble Fibonacci spirals, which are found in sunflower seeds, pine cones and snail shells. The Core, as it is known, has taken two years to build and will house exhibits and ecology models for Eden's eco-park. The double curved beams for the roof are from a Forestry Council sourced spruce forest in Switzerland and copper for the roof panels comes from a sustainable mine in Kennecott, Utah.