One of the last travertine rarities from Germany is of travertine special book. It is in the District Sonderbuch of the town Gemeinde Zwiefalten in the Landkreis Reutlingen in Baden-Württemberg. This limestone was formed by deposits of a freshwater lake on the edge of the Swabian Alb. Dissolved in water lime coated contained in the lake of dead animals and plants and formed a rock layer, a travertine of extraordinary appearance. Travertine special book is also frost-resistant and weatherproof. For centuries, just travertine was preferably used in public buildings and equipment, castles and churches, since it 'convinces with an elegant understated, purist aura says Ulrich Klösser from Traco. Therefore, he has made the rediscovery exceptional limestone and sandstone to the task. Sandstone, travertine, limestone from the classic quarries of Weimar, Gotha, Bad Langensalza, Zwiefalten ... stones that already Goethe fascination excited. From Mies van der Rohe and other Bauhaus architects such as Peter Behrens and Erich Mendelsohn preferred.