Gerolstein is best known for water, and the water is the story of the place. The town lies in a bowl of the Kyll valley, and under it flows mineral water from the volcanic ground, rich in carbonic acid and minerals, which is bottled and sold across Europe under the town's name. You can see the factory at the edge of town and taste the water at the public springs, where it comes out fizzy, cool and slightly metallic. About seven and a half thousand people live here, so fuel, shops and restaurants are plentiful.
The surroundings are geologically odd. Cliffs of grey dolomite, a limestone-like rock formed in a warm Devonian sea about four hundred million years ago, rise abruptly above the town, with names such as the Munterley and the Hustley, and the paths up to them give fine views. The Buchenloch cave, in the same cliff, was lived in by Stone Age hunters, and bones of mammoths and cave bears have been found. Nearby, the Eifel's volcanoes left behind craters and cinder cones, and the area is part of a UNESCO Global Geopark.
A few kilometres to the east, at Pelm, the Kasselburg castle ruin stands on a rock with a wolf and bird of prey park on its slopes. The flying displays in the afternoon are a favourite with families. In town, the Erlöserkirche, a Protestant church of the nineteenth century, has a plain brick tower. Local food in the Eifel is hearty and unfussy, with potato dishes, smoked ham and sausages and plenty of apple cake, and the Kyll valley has good trout.
The Eifel Volcano Route ends here, after a long ride through craters, forest and moorland, and for the final stretch the roads follow the river through shaded valleys with gentle bends. The surface is generally good, the traffic modest, and the landscape rolling, though the weather can be cold and foggy. Autumn is spectacular, with beech and oak turning red and gold, and the maar lakes lying like dark mirrors. Winter can bring ice and snow to the plateau, so the high roads can be tricky. Gerolstein itself is a pleasant spot to finish, with a bench by the river and a bottle of the local water.