Which region in southwest France is known for producing Malbec-based red wines?

Cahors is recognized for its production of Malbec-based red wines, often referred to as "Cot" in this region. The distinctive soil composition and climatic conditions of Cahors contribute to the unique character of its Malbec wines, which are typically characterized by deep color, robust tannins, and dark fruit flavors. Historically, Cahors has been significant for the cultivation of Malbec, especially before it became more widely recognized in Argentina, where it gained international acclaim.

The other regions mentioned, while notable for various wines, do not have Malbec as their primary or defining grape. Jurançon is primarily known for its sweet white wines made from Petit Manseng and Gros Manseng. Madiran is celebrated for its Tannat-based wines, which display rich tannins and bold flavors. Bergerac produces a variety of wines, but its main focus is on blends, particularly those involving Merlot and Cabernet Sauvignon, rather than on Malbec. Thus, Cahors stands out as the region synonymous with Malbec production within southwest France.