A steel engraving made by Alexander Marx in 1845. The arch over the river is 13 meters high and 14 meters wide. Inside the left hand part is a small and inside the right hand part is a large hall. The pointed arch hall inside the right hand (southern) part has a wide of 20 and a height of 12 meters. Except on special days as e.g. "Day of Technical Monument" the halls can unfortunately not be entered.