by the Schluchseewerk AG. The Alb then flows through a wide valley, lined by meadows, which contains the villages of Schlageter and Immeneich. The valley is no longer bordered by narrow, wooded ridges, but instead by the undulating Hotzenwald plateau in the municipalities of Dachsberg und Höchenschwand. The plateau is indented by bogs and rocky hilltops. During the Würm ice age, the Alb glacier ended at the point where we now find the village of Niedermühle. With a length of , the Alb glacier was the longest in the Black Forest. Downstream of Niedermühle, the valley is very narrow, leaving no room for settlements. Alb Gorge The slope of the Alps increased greatly in the ravines and the river forces its way through the more canyon-like passages and blocked sections known as the ("Devil's Kitchen"). The Ibach and Höllbach join from the right, each emerging from its own narrow gorge. The Höllbach has two waterfalls in this area. Because the gorge is so narrow, the road is up to higher, on the left bank. On a wider spot in the valley, is the saw mill Tiefenstein and two tributaries, Schildbach and Steinbach. Halfway up the slope, there are granite quarries and the ruins of two castles. The narrowest and most dangerous passage begins downstream of Tiefenstein. Long ago, the Alb followed a different course and flowed to Hauenstein through the valley now occupied by the Mühlbach. This route was blocked by glacial deposits during an earlier ice age, forcing the Alb to find a new route to the Rhine. Since then, the "new" gorge cuts through the granite rock. This section cannot be travelled without special equipment, even though the water flow is usually low, because most of the water has been diverted. It there is sufficient water, canoeing is possible, although this is considered the most difficult stretch of whitewater in Germany. In this section the road runs up to above the river and passes through five short tunnels drilled through the cliffs, giving it the nickname "Axenstraße of the Black Forest". From the hamlet Hohenfels, the road descends to the valley floor at Albbruck, where the Alb flows into the High Rhine. Gallery See also Alb (Northern Black Forest) Footnotes Rivers of Baden-Württemberg Rivers of the Black Forest Rivers of Germany