In Marktschellenberg, the wild water of the Almbach has dug deep into the flank of the Untersberg and formed the gorge of the Almbachklamm. The gorge is accessible via steps, bridges, and tunnels under which the wild torrent rushes towards the valley. At the lower end, the water feeds Germany’s oldest marble ball mill. Since 1683, chunks of Untersberg marble have been ground into fine spheres with water-powered whetstones.