The route starts at the Mühlenthal hotel in Schwalbach near Saarlouis. You leave for Saarlouis, then drive outside to Völklingen where you can visit a cemetery for soldiers who died in the Second World War (RP3). In Völklingen, an old iron smelter has also been converted into the Weltkulturerbe Völklinger Hütte cultural center. Nice to walk through. If you want to see everything, just take a day for it, that's how big it is.

Then you cross the Saar. You will now pass two mining museums: Erlebnisbergwerk Velsen (RP6) in Germany and just across the border in France Les Mineurs Wendel (RP7). Choose 1 (for example whether your German or your French is better) and take a look. The German is more of an amusement park, the French is more authentic. Subsequently, the forests, rural areas, villages and more industrial areas alternate quickly. At Hambach you can visit the Smart factory (RP13). You will arrive in Sarralbe, where the Ligne Maginot Aquatique can be viewed in the museum, when it is open (RP17). A great place also for a coffee stop and to take a look at the town with a beautiful church.

Enjoy the beautiful roads that you are now going to drive. Enjoy swinging and swaying along forests, grain fields, over bridges and along streams. After which you arrive in Mittersheim. Here you can drive along the reservoir. The route takes you along it. You do drive a round through Mittersheim because it has a piece of one-way traffic.

Then you drive through forests and along (reservoir) lakes into the Lorraine. After some time you come to the Col des Français, where you cross a canal (RP25). Further on you can visit the lock Grande Ecluse de Réchicourt (RP26). This lock has a high drop. It replaced 6 locks with a lower drop. This resulted in a time saving of more than 5 hours. RP28 has a snack bar. What you get there you can eat a little further on the reservoir. A wonderfully quiet spot for lunch, on the reservoir (RP29). At Morhange you can refuel if necessary (RP35).
At Laudrefang you will find many remnants of the Ligne Maginot, hidden in the landscape (RP40). At Karlsbrunn you can have a drink in the Biergarten im Jagdschloss Karlsbrunn (RP45). Just beyond it is a large solar park (RP46). After this you will go back to Saarlouis, Schwalbach and the hotel via some villages.

I drove this route myself in 2017.

I give this route 4 stars. It is again a very varied route with a number of nice sights and beautiful roads.