At the "Roter Puhl" the Enz has cut the beech slope at a stately height. Here, in bright orange-red colors, the middle red sandstone rock of the Triassic geologic age can be seen. These deposits in river and delta areas are about 220 million years old.
The oblique stratification of the sandstone visible in the bedrock in alternating layers with horizontal strata and gravel bands testifies to the different flow conditions of the primordial waters. The arch's shape is the result of thousands of years of exposure to water from the meandering Enz River.
The surface of the rock face is still subject to constant weathering, in places the rock is slightly more porous. An interesting insight into the floor structure can be obtained in the upper part. The overlying Earths here only reach a thickness of less than a meter. Natural crevices provide nesting and breeding grounds for the kingfisher, which is native to the area.