The GEOpath

The GEO trail provides an excellent insight into the geological history of the Bergisch Gladbach area. Landforms, botany, industrial monuments, and quarries are explained on 17 information panels. The numerous fossils, some of which were discovered here for the first time, dating back to the prehistoric Devonian sea 350 million years ago, are known to experts worldwide.
Over 400 million years ago, the collision of various tectonic plates created a vast northern continent (the Old Red Sandstone continent) stretching from North America to Siberia. Between 390 and 360 million years ago, during the Devonian period, the southern coast of this continent lay in the Bergisches Land region of Germany. Present-day Europe was then located south of the equator. Tropical climatic conditions prevailed. A warm, shallow sea dotted with islands covered large areas of the Bergisches Land. Coral stromatoporoid reefs grew up around the islands and on the shallows. Stromatoporoids are sponge-like reef builders that became extinct about 100 million years ago.
In Bergisch Gladbach, the Schlade valley, situated within a nature reserve, offers an excellent overview of the diverse habitats of a primeval reef – from the surf zone to the reef lagoon. The Schlade is a dry valley. No watercourse flows through its sometimes quite wide valley floor. This is due to the water solubility of the limestone. Watercourses in areas with limestone bedrock often follow an underground course along fissures and cracks, which can expand into caves as the limestone dissolves further. However, the Schlade also owes its current appearance to human activity, specifically the industrial mining of limestone and brown iron ore, primarily during the 19th century. The most scenic spots can be accessed via the Bergisch Gladbach Geo Trail, maintained by the Sauerland Mountain Association (SGV).
The Schlade is one of the most important geotopes in the Rhineland and has been a National Geotope since 2006 – one of 77 in Germany. It also offers botanical features and, with its ore mines, limestone quarries, and kilns for quicklime production, provides insight into the economic history of the Bergisches Land region.