The Bühl near Ahnatal-Weimar, northwest of Kassel, became famous through the discovery of solid iron in the deeper levels of the quarry. Masses of up to 13.7 kg were recovered. The reason for the formation of the iron is the contact with tertiary lignite under the basalt. Unfortunately, a clay collapse occurred during blasting in 1925, which flooded the quarry in a short time. No more finds have been possible since this time.