The Château de Fajac la Relenque is located in the commune of Marquein, just south of Toulouse and Carcassonne (45 min drive from either via the A61) in the Occitanie region of southern France. It is just off the D7.
Adress for your gps: La Grange 11410 Marquein which the beautiful house nearby (as lots of gps do not find le château de fajac la relenque, Marquein 11410)!
This map shows the exact location.