There is an old sluice in Germany which looks like it is made completely out of stone. That is not the case any longer. During the last restoration, a precast concrete wall was added, which was designed so perfectly that the change is not noticeable. This wall is the work of DUHA Fertigteilbau GmbH. The company is an expert for precast concrete products, prefabricated commercial construction and structural engineering. The German company has already carried out a number of unusual projects.