Castelnau-de-Montmiral is a commune in the Tarn department in southern France. The Vère flows westward through the commune. While traces of activities dating back to the Bronze Age such as dolmens and oppidums can be seen in the nearby forest La Grésigne, the village was founded as an albigensian bastide in 1222 by Raymond VII, count of Toulouse, under the name “Castellum Novum Montis Mirabilis”.