The Selberg is a volcanic spring crest, the molten rock of which solidified under the earth's surface about 36 million years ago. The special form of the rock is clearly visible at this point. The occurrence of tensile stresses resulted in more or less uniform, predominantly hexagonal columns. The columns are perpendicular to the cooling surface. The stone that was used to build houses in Quiddelbach, among other things, is a Benmoreit.