The Kammergraben is the path that leads from Bleichheim up to the castle meadow and on to Kürnberg Castle.
Halfway up to the castle meadow there is a tunnel mouth in the hillside in the Kammergraben in the Gewann Bergmannsloch. If you climb this slope to the west, after a few meters you will find a so-called pinge in the forest. A pinge is a funnel-shaped depression in the terrain that was created by mining operations, where the vertical entrances into the mine tunnels collapsed and the soil above slipped.
The chamber moat was once owned by the Meiger von Kürnberg, vassals of the Lords of Üsenberg and bailiffs of Kürnberg Castle. They had probably already been mining here in the late Middle Ages.
Further Pingen are located northwest below Kürnberg Castle on the Ölberg and along the Kammergraben. The ore deposits here were very sparse. Brown iron stone, manganese iron ore and galena were primarily mined here. But there are also numerous references to mining activities on the Kirnhalden, east of the castle on the Erzbuck.