On a summer morning in August 1888, a woman named Bertha Benz took her two teenage sons, climbed into her husband's new Patent-Motorwagen without telling him, and drove from Mannheim to her mother's house in Pforzheim. It was about a hundred kilometres, the first long-distance journey by motor car, and it was a piece of brilliant publicity as well as a family visit. She bought ligroin, a petroleum solvent, from a pharmacy in Wiesloch, which is considered the world's first filling station, used a hat pin to clear a blocked fuel line and her garter to insulate a wire, and had a cobbler fit leather to the brake blocks, thereby inventing brake lining. The Bertha Benz Memorial Route follows that trip, and here is where it ends.
Pforzheim, called the Golden City, lies at the northern edge of the Black Forest, where three rivers, the Enz, the Nagold and the Würm, meet. It has been a jewellery and watchmaking centre since the eighteenth century, when the Margrave of Baden founded an orphanage that made watches and jewellery to support itself, and the industry grew from there. On 23 February 1945, a British air raid destroyed most of the old city and killed a large share of its people, and the town was rebuilt in the plain postwar style, which means it is not pretty, but it has strong character and good museums. The Jewellery Museum is worth a visit.
With about a hundred and twenty thousand people, Pforzheim has fuel, shops and services in plenty. The ride from Mannheim runs mostly through gentle country, with orchards, vineyards, castles and the half-timbered towns of the Kraichgau, then rises into the northern Black Forest. It is a gentle road, mostly through villages, with slow traffic and many roundabouts, and the pleasure is in the history, not the bends. Look for the signs with the route's emblem, and you can follow it without a map.
For a good night, there are plenty of hotels, and the local Swabian food is filling, with Maultaschen, spätzle and onion roast beef. Spring is lovely in the Enz valley, when the orchards bloom, and autumn is golden. Rain is common, and the northern Black Forest is cool and often misty, so pack a waterproof. A tank of fuel in Pforzheim is a small tribute to a very brave woman.