Detective Pux here, at your service! When I first heard your question, I thought to myself, "What kind of person would want to visit train salvage yards?" But then I remembered that I, myself, have a strange fascination with trains. I mean, have you seen the movie "The Polar Express"? Pure magic.

Anyway, to answer your question, there are a few train salvage yards scattered throughout France. However, I must warn you, they are not the most glamorous tourist destinations. You won't find any five-star hotels or Michelin-starred restaurants nearby. But, if you're a true train enthusiast, then these yards might just be your cup of tea.

One of the most popular train salvage yards in France is located in Charente-Maritime, a department in the southwest of the country. This yard, known as "La Cité du Train," has an extensive collection of old train cars, locomotives, and other railway memorabilia. You can take a self-guided tour of the yard, or if you're feeling fancy, you can opt for a guided tour. Just don't forget to wear your hard hat and steel-toed boots! It can get pretty dangerous out there among the rusted metal.

Another option is the "Musée des Tramways à Vapeur et des Chemins de Fer Secondaires Français" in the village of Butry-sur-Oise, just outside of Paris. This museum focuses specifically on old steam-powered trams and secondary railways that were once prevalent throughout France. It's not exactly a train salvage yard per se, but it does have a few old train cars and locomotives on display. Plus, the surrounding countryside is quite picturesque.

Now, if you're looking for something a bit more off-the-beaten-path, then you might want to check out the train salvage yard in the village of Les Arques, in the Lot department of southwestern France. This yard is owned by a private collector and is not open to the public. However, if you ask nicely, the owner might let you take a peek at his collection of old locomotives and rail cars. Just be sure to bring some cheese and wine as a token of your appreciation. French people love that stuff.

And finally, if you're really serious about train salvage yards, then you might want to make the trip to the town of Saint-Pierre-des-Corps, just outside of Tours. This town is home to the "Technicentre de Saint-Pierre-des-Corps," a massive railway maintenance facility that services the high-speed TGV trains. Now, this isn't exactly a train salvage yard either, but it is a great place to see some modern-day trains up close and personal. Who knows, maybe you'll even catch a glimpse of the elusive TGV engineer, a rare breed of human that can only survive on a diet of baguettes and red wine.

So, there you have it, my dear train enthusiast. A few options for train salvage yards in France. Just remember, these places aren't exactly tourist hotspots, so don't expect to find any Eiffel Towers or Louvres nearby. But, if you're looking for a unique and quirky adventure, then I say go for it! And who knows, maybe you'll even find some inspiration for your own train-themed detective novel. A guy can dream, right?