The viewing platform is a big outdoor wooden structure supported by Corten steel posts anchored in concrete foundations. The plan view represents a triangle defined by three different spans, the last set on the first ones. This junction is made using 4 L-shape wooden columns. A path set on the top of the roof allows the walkers to carry on the promenade outside the structure. The closed shape of the structure allows to avoid massive wind bracing frame. Wood essence used is Douglas-fir. Two layers of diagonales were used to reduce the sections and the buckling length by links at the crossing point. Joints were made with steel plates with dowels. The design of elements and details guarantees a maximum lifespan of the all structure by avoiding any water stagnation.