Located at the foothills of the Montagne Noire in the Tarn department, the village is situated on a small promontory (209 m) overlooking the valley of Sor, on the north bank of the river. Crossed by the RD 84, main axis serving the town and connecting the two axes that join Toulouse. Blan is halfway between Revel and Puylaurens.
Some important personages were born where the commune lived:
- Admiral Jaurès, brother of Jean Jaurès, whose parents, the Duprats, built a dwelling house which is located at Blan chemin de Lamothe, opposite the cemetery.
- The general, Count de Las Cases, who wrote the memorial of St. Helena, was born at the place called "Las Cases" in 1766 and died in 1842.
- Elisa Lemonnier, born in Sorèze in 1805 and wife of Charles Lemonnier, professor of philosophy at the Sorèze school. In 1862, it created the first vocational school for women in Blan. The success was such that other institutions opened their doors. The spouses Lemonnier resided at length in Blan, in the property of Montpinier.
