The start and end point of the circular trail is the church of St. Johann Baptist in Simmerath. The origins of the white hall church date back to the 14th century. It is modeled on a Roman basilica and is still quite young in parts. The old church was almost completely destroyed in the Second World War before being rebuilt in 1952 by the energetic population and generous donors.

We leave Simmerath in a northerly direction and after around one kilometer we come across the small river Kall, which meanders from the eastern edge of the High Fens for 25 kilometers to Zerkall, where it flows into the Rur. In the section between Simmerath and the Kalltalsperre dam, the Kall is an almost undeveloped, free-flowing low mountain river. Together with the side valleys criss-crossed by smaller streams, the Kall valley forms an ideal retreat and distribution area for the typical biocoenoses of the near-natural waters of the Rur Eifel. In addition to the populations of many rare plant species, this also includes the populations of beavers, kingfishers and rare bat species. Due to this biodiversity, the valley has been a nature reserve for almost 20 years and therefore offers a pure nature experience.

We follow the course of the valley, accompanied by the babbling of the Kall, for around 2.5 kilometers and reach the remains of Mathar's mill shortly after crossing the B266. The Lammersdorf mill with its residential building, stable and barn was first mentioned in a document in 1516. It was one of the so-called "Bannmühlen" (ban mills), where people from the region had to have their grain ground. When Josef Mathar, the last miller, died in 1955, the complex fell into disrepair and was demolished in 1970. Today, the old millstone and a cross are reminders of the mill.

Continuing along the Kall, you finally reach the Kall dam. Built in 1934, the dam holds over 2 million cubic meters of drinking water and not only supplies the city of Aachen and parts of the district of Heinsberg with water, but also offers a fantastic view.

Along the banks, the trail leads around the entire dam. At the north-eastern tip of the reservoir, it passes the so-called Kaiserfelsen. The rocks made of massive devo rock on both sides of the path are truly imperial. Where the path bends to the left, you have a beautiful view of the natural monument.

Along the eastern bank of the dam and then through forests and meadows, the trail leads back towards Simmerath. Shortly before reaching the village, we come across the so-called Lönsfelsen, named after the local poet and nature lover Hermann Löns (1866-1914), who made a heartfelt declaration of love to the landscape of the High Fens with his multi-layered description of a mating hunt. Since 1926, a relief on the west side of the rock has commemorated the poet. In addition to the inscription "Hermann Löns", it also depicts his favorite bird, the owl. From here you have a beautiful view in the direction of Lammersdorf before the path leads us back to the starting point of the tour.