It is a challenge to get to KL Natzweiler-Struthof, but the Nazis deliberately chose remote locations for their operations. Additionally, this location was chosen to be able to mine pink granite for the Reich's building program. It was initially populated by prisoners transferred from Sachenhausen and was primarily a political prisoners' camp, but others were brought here as well. A collection of Jewish skeletons was started by the doctors. Cadavers were provided from its operational gas chamber upon requests from German medical schools. Allied PoW's and resistance fighters were brought here to be killed. The crematorium was kept busy, and many urns were stockpiled for planned use.
The Americans found the camp empty, as the inmates were force-marched to Dachau. It is still sparsely visited. The French claim it was the only German camp on French soil, but that ceratinly doesn't explain Vittel, or the French-run camps like Pithviers, Rivesaltes, St.Sulpice, St. Cyprien, Les Mazures, Drancy, or Gurs. In any event, it is still an eerie place to be. BTW, the former commandant's house still stands in good repair. It is now in private hands, along with its original swimming pool.