If the South of France has become known as the "new" New World of wine, the south-west is its new old world. From the sunny foothills of the Pyrenees through Toulouse across to the spine of the Massif Central, the south-west is a sprawling, diverse wine region on the brink of rediscovery. Bisected by the Garonne River, the Quercy side fans out east of Toulouse past gluggy Fronton to the long-lived wines of Cahors and sprightly Gaillacs and includes some of France's most obscure appellations, among them Marcillac, Estaing and Entraygues et Le Fel. To the west, the Gascon left bank of the Garonne is home to inky-dark Madiran, dry and sweet Jurançon, everyday Saint Mont and the weirdly-named, quasi-separatist Basque appellation of Irouléguy.

The wines of south-west France are the modern fruits of a medieval tradition struck down by the phylloxera plague in the 19th century. As the vines withered, it found itself upstaged by Bordeaux and Languedoc-Roussillon, whose superior lines of transport allowed them to bypass this once flourishing wine region. But a few visionary growers and outside investors have brought about a revival of the fortunes of this obscure part of France's treasure chest of wines. What marks this region out is its wealth of idiosyncratic flavours derived from native grape varieties such as tannat, malbec, négrette and fer servadou (reds) and petit manseng, gros manseng, courbu, mauzac and len de l'el (whites).

On the steep vine terraces of Marcillac in the eastern Lot Valley, Philippe Teulier uses the herby fer servadou, here known as mansoi, for his excellent 2007 Lo Sang del Païs, Domaine du Cros, £7.99, Les Caves de Pyrène, a bright, nettley red with a capsicum-like aroma and supple raspberry and blackcurrant fruit. To the north in the gravelly soils of the Tarn valley, neighbouring Gaillac used to make more wine than Bordeaux in the 1850s until it fell on hard times. Gaillac's increasingly excellent whites, sweet, dry and sparkling, are made from the native mauzac and len de l'el, aka loin de l'oeuil. For a good example of the latter, try Domaine Rotier's 2007 Gaillac Sec Renaissance, £10.17, Vine Trail (0117 921 1770), a peachy dry white with a tangy herbal finish.

Immediately to Gaillac's west is Toulouse whose own wine district of Fronton, which straddles the Garonne, is known for the négrette grape. This ancient variety is Toulouse's answer to beaujolais' gamay, producing typically perfumed, juicy sausage-friendly gluggers such as the 2007 Château Marguerite, Fronton, £6.99, Stewart Wines, Bristol (0117 962 0956). Head north of Toulouse and you eventually reach Cahors, the south-west's biggest and most historic appellation which sits in a horseshoe bend of the Lot River. Cahors has been the master of reinvention, its growers taking advantage of modern winemaking techniques to transform this sleepy district into a vibrant modern wine.

Cahors is of course the French home of the malbec, known as cot or auxerrois until Argentina came along and gave it an image makeover as malbec. It's here that passionate growers like Pascal Verhaeghe of Château du Cèdre, have worked their socks off to produce superbly rich and concentrated reds like the 2005 Château du Cèdre, Le Cèdre, around £20, Lea & Sandeman, Great Western Wines, Les Caves de Pyrène, £24.99, with its vanilla-suffused aromas and black cherry and chocolatey-fruit quality. Coming soon: the wines of Gascony and the Pyrenees.