This barren plateau between Valladolid and Aranda, self-styled roast lamb capital of the world, is currently producing some of Spain's most admired red wines, to the continuing amazement of the peasant farmers who have lived on the banks of the Duero river for generations. Downstream and over the Portuguese border, their counterparts farm port grapes in what is known as the Douro Valley. But whereas port has been famous for three centuries, the wines of Ribera del Duero are a relatively recent phenomenon.

Only at the end of the 19th century did one producer, now called Vega Sicilia, gain some sort of recognition for the intensity of its wines. And it was not until the mid 1980s that another, an agricultural machinist Alejandro Fernández of Bodegas Pesquera, managed to establish the region as a viable source of high-quality, long-lived, concentrated, deep-coloured wines. The DO classification was not granted until 1982 and since then there has been an invasion of investors keen to transform often highly unsuitable parts of this high plateau into profitable wine production centres.

It is the altitude, about 2,000 feet, which keeps nights cool and extends the grape ripening process until well into October, sometimes November in a particularly cool year. This means that the grapes are harvested with very high levels of colour and flavour. Most of the vines grown are  the locally adapted version of Tempranillo - which is so common here it is  called simply Tinto (red) Fino - but Cabernet Sauvignon, imported as far back as 1864 at Vega Sicilia, Garnacha, Merlot and Malbec are also permitted. Rot rarely threatens in the crisp dry air of this table land with its little mesas and clumps of umbrella pines. Spring  and even autumn frosts, on the other hand, are a perennial danger. This is jumper country; it has nothing whatever in common with Spain's popular Mediterranean image though it gets pretty hot (35 degrees C) in the middle of a summer day. Flocks of long-haired sheep are still driven along the main roads.

A high proportion of the locals have always made some wine for their own consumption. Almost all of those with some to spare used to sell it to the co-operative in Peñafiel in the centre of the region. But since Pesquera became a cult wine in Madrid and the United States, all manner of bodegas have sprouted up, some of them showing the same sort of vibrant potential as Pesquera but many of them clearly opportunists rather than skilled winemakers and some producing decidedly overpriced wines. The correlation between price and quality within this DO is particularly variable here.

Thanks to a policy of maturing wine in small barrels for years longer than any other producer I know, Vega Sicilia produces a very individual, and necessarily expensive style of Ribera del Duero. Pesquera's modern style of bottling the wine after just three or four years in cask is more commonly adopted by the newcomers - for obvious financial reasons, but also probably because the livelier style of the wine itself finds more favour with modern wine drinkers.

Some favourite producers (some of them just west of the official boundary): Aalto, Abadía Retuerta, Alión, Dominio de Atauta, O Fournier, Hacienda del Monasterio, Mauro, Emilio Moro, Pesquera, Dominio de Pingus, Teófilo Reyes, Vega Sicilia, Alonso del Yerro.