The new observation tower on the River Mur (Southern Styria, Austria) opened to the public just in time for the beginning of spring 2010. The design for the sculptural structure set amidst the landscape of the European habitat system “Green Belt” was developed by the Munich-based architects and landscape architects, terrain:loenhart&mayr, who are renowned for the new and trend-setting Olympic Ski Jump in Garmisch-Partenkirchen. With the look-out on the banks of the River Mur, the observation tower offers access to the ecology of the surrounding floodplain forest and lets visitors experience the river catchment, which changes according to the intensity of the water’s flow.
The access and construction principle of the Mur Tower is based on the idea of a double helix that is perceived as a continuous path rising up through the trees. The visitors’ climb to the top is a scenic experience. The circular path, ascending to the top like a screw, passes through the different levels of the forest – the ecological storeys of the floodplain forest – and enables visitors to experience the eco system and the microclimate of the forest. Eventually, after 168 steps, at a height of 27 m, the observation platform is reached. This was deliberately kept small and offers wonderful panoramic views of the surrounding countryside. A second flight of stairs leads down from the platform so that ascending and descending visitors are actually moving through the defined space on different flights of stairs.
There is a surprising link to the historical double spiral staircase in Graz Castle. The architects of the Mur Tower were inspired by that staircase built around 1500 and well known for the unique spatial atmosphere it creates. In a homage to this historical site, the Austrian poet, Erich Fried, wrote that “the double spiral staircase connects space and time like a screw”. The connection between space and the experience of climbing up and down is the basic idea behind the spiral-shaped paths of the Mur Tower.
In collaboration with the structural planners, a polygonalised spatial structure was developed, which took into account all aspects relevant to the structure and the technical production. Significantly, an integrated approach was adopted for the design process – after some preliminary model studies were prepared, the model designs were statically dimensioned in digital domains to then once again be checked from an architectural point of view in physical models. This process was repeated several times until the desired interplay of form, motion and structure was established.