The Oker is the river that cuts the Harz in two, and the road that follows it from Goslar toward Altenau is among the best in northern Germany. The valley is narrow and steep, with dark spruce forest on the slopes and bare granite cliffs breaking through, and the road keeps close company with the water, bending with every meander. The corners come one after another, tight enough to keep you busy and open enough to enjoy, and the surface is generally good.
The valley holds the Okertalsperre, a dam built in the 1950s to supply drinking water and control floods, which forms a long lake behind a massive wall of masonry. The lake is a deep green and the shore is quiet, and the walk along the dam is a pleasant way to stretch after the bends. Further down the valley, a short footpath leads to the Romkerhall waterfall, a small cascade in a rocky gorge, and above it the cliffs known as the Adlerklippen, where eagles were once said to nest, offer a view over the forest.
The Harz is one of Germany's oldest mountain regions, a block of ancient rock that was pushed up long ago and then worn down, and its highest point, the Brocken, is famous in German literature as the place where witches gather on Walpurgis Night. The mists that gather on these slopes make the legend easy to believe, and the forest has a haunting quality in cloud. The bark beetle has hit the spruce woods hard in recent years, and the dead trees on some slopes are a sad sight.
The road is popular with riders, and it pays to keep to the posted limits. Weekends are busy, and mid-week mornings are best. Fuel is not on the valley road itself: Goslar, six kilometres away, is the big town with everything, and Bad Harzburg, nearly eight kilometres, is a good alternative. Altenau, at the top, is a small resort with cafes. Late spring, when the forest is fresh, and autumn, when the beeches turn, are the best times to ride.