“Steinerne Rinnen” or calcareous tufa gutters are rare karst phenomena. The main occurrence of such kind of gutters is in the hilly areas of Franconia, in the northern part of Bavaria in Germany. It would be interesting to know if such geologic gutters can be found elsewhere as well as the local names for such formations. The formation of such karsts require a fountain rich with dissolved carbonate, a terrain steep enough for a fast-running stream, and some mosses or algae in or near the water. In this case, sedimented tufa slowly forms a certain kind of a wall-like structure with the water-stream on top of it. The longest gutter in Germany is approximately 150 m long. The tallest known gutter reaches a height of 5.4 m. The natural protection state of a “Steinerne Rinnen” can be different. Sometimes they are protected as a natural monument or registered by a so called geotope. Others are simply part of a larger protected area.