When we hear of tower, concrete materials instantly registered into our minds. However, designers from Institut fuer Konstruktion und Gestaltung (KoGe) have developed an eco-friendly tower for the Carton Plein exhibition in Paris made entirely of cardboard. With a height of 10 meters, the cardboard tower uses the simple folding principle. The reason behind the creation of this green tower is to occupy the empty space the Pink Staircase has. Located at the center of the round staircase, the cardboard staircase was able to amuse people as the step upward whilst keeping the environment safe through the materials use and eventually reminding all people to stay and live green.