Peñafiel, Spain

From the parapet of the castle ruins, the world spread out before us, bathed in the soft colors of the early evening. The valley of the Duero River, its banks dotted with white stone hamlets, stretched to the horizon, and medieval Peñafiel, a town of dusty streets and red-roofed houses, hugged the castle hill. A patchwork of vineyards and fields of wheat and rye carpeted the valley floor and crept halfway up the steep valley walls, and the brilliant red of wild amapola flowers splashed across the landscape, not in demure droplets but in giant puddles like cans of spilled paint.

The scene sent us spiraling back to a time of royalty and romance.

Then Hayley laughed softly, breaking our reverie, and I had to smile too. The setting had cast a spell, one best shared with a boyfriend, not with one's mother. But at 16, she had the grace to realize that a mother-daughter wine trip to Spain, while hardly the stuff of romance, could have its moments.

We had many in our week on the road in Ribera del Duero, the river valley 90 minutes north of Madrid. I came here to learn about the region's hedonistic red wines, wondering whether Ribera del Duero would have staying power as a major wine region. Hayley, with four years of Spanish classes behind her, was to be translator as we roamed Spain's most dynamic wine region, a vein of vineyard gold in a rich agricultural plateau that has begun to come into its own.

Until recently, Rioja was the traditional pinnacle of Spanish wine culture and the country's hottest ticket in wine tourism. The Frank Gehry-designed Hotel Marqués de Riscal in this northeastern region of the country has helped keep it a top tourism draw.

But the wines of Ribera del Duero have eclipsed Rioja's. Ribera's wines are pricier and its leading winemakers, including Mariano Garcia, Peter Sisseck, Alejandro Fernández and Xavier Ausas at the venerable Vega Sicilia winery, are now Spain's superstars. And critics are swooning over Ribera del Duero's rich, jazzy Tempranillos, drawing wine lovers like me to taste and see and, perhaps, join the ranks of believers.

Ribera was named a Denominación de Origen, the official distinction for classified Spanish wine, just 25 years ago. But for a millennium before that, winemaking was a family tradition here. This valley also was the playground of the Spanish royals for centuries, and their palaces and churches have survived to tell their story.

Our June journey took us not just through vineyards but across centuries.

UNDERGROUND WINERIES

Peñafiel, with its imposing 15th century castle, is the soul of this region, although not necessarily its geographic center, and Castillo Peñafiel is the right place to begin exploring the 75-mile heart of this river valley.

The regional wine museum inside the castle is designed for serious enthusiasts who care about the details of viticulture and winemaking, although the guidebooks and exhibit notes are only in Spanish. (A handy guide, "Vinos de la Ribera del Duero," which has a description of the region's major wineries, is available in the museum shop, but it also is in Spanish.)

On the hillside at the base of the castle are a dozen 8-foot-tall stacks of stones. These are ventilation shafts above the ancient underground wineries, called bodegas in this part of the world, that local families still use in the making of homemade wine. To visit this subterranean world, you must be lucky enough to catch someone who can be persuaded to offer a tour because none of them is open to the public. Despite knocking on several of the old wooden doors, we never got lucky.

Five medieval church steeples define Peñafiel's skyline, and when the sanctuaries are open, they are glittering examples of provincial ecclesiastical life, proof that this land was the home of kings and princes.

In the late 1400s, Spain's ruling monarchs, Fernando of Aragon and Isabel of Castilla, made their home in Valladolid, the region's capital, and presided over the Spanish Inquisition. By the middle of the next century, the royal court had moved to Madrid.

Although it is in Valladolid province, Peñafiel's most picturesque architectural landmark is the humble Plaza del Coso, a circle of three-story homes built shoulder-to-shoulder to form a bullfighting ring. (We missed the fights, which take place during the Festival San Roque in the 100-degree heat of August.)

The plaza was so modest that what came next was a surprise.

We had chosen to stay at Convento Las Claras, which overlooks the town's lush central park along Río Duratón, a tributary of the Duero. Las Claras, a 400-year-old polished white stone convent, was reborn last year as a luxury hotel, and we decided to take full advantage of its amenities.

After our drive, we made the indoor spa pool the first order of business. We relished the powerful jets and also stood under a waterfall until the skin on our fingers was as wrinkled as raisins.