SIENA, Italy — The maze of one-way streets leading into Siena's gated old town yielded a magnificent reward.

The first European city to ban cars and mandate a color scheme consonant with architectural tradition, preserving the historic center, is now a UNESCO World Heritage Site.

Etruscan archaeological remains suggest that the city was founded at least as early as Rome. But Siena is one of the most splendidly intact Gothic cities in Europe. During the 13th and 14th centuries, it competed for power with Florence and its banks propped up cash-strapped popes and kings. Siena's Monte dei Paschi bank, which opened in 1472, continues to underwrite civic projects that give the town of about 60,000 an air of prosperity and sophistication.

Siena is a red-brick beehive built across three steep hills. My sister Martha and I checked into the Palazzo Ravizza, a small hotel above the city walls. Our well-heated rooms had heavy, old-fashioned furniture and windows overlooking the garden whose miniature orange trees were covered in protective plastic.

In early spring's spitting rain, we climbed to the cathedral. The building's famous western facade of black and white marble was encrusted with saints and angels. I thought of other Gothic churches I had admired in Europe — Westminster Abbey and Chartres Cathedral — but the Siena Duomo was breathtaking, I decided.

Wandering deeper into town, we emerged into Siena's shell-shaped "campo." It's paved in brick, and native son Jacopo della Quercia's carved 15th-century Fountain of Joy is embedded near the crest of the slope, facing the campanile of the Palazzo Pubblico.

We had tea and "panforte," a Sienese fruitcake too thick to cut with a fork, at a cafe on the campo. With the campo virtually empty and our boots ringing eerily on slick stones, we visited the museum in the Palazzo Pubblico. It was built around 1300 and decorated by Italy's best Gothic painters to exalt Siena's civic and religious spirit.

With the gallery to ourselves, we lingered at its prize, Simone Martini's "Maesta," a group portrait of the Virgin Mary surrounded by saints. The Madonna is much more than Siena's patroness. She is its personal protector and divine governor who, according to legends, ignores the prayers of those who oppress the weak.

Next door in the meeting room of the Council of Nine, a group of oligarchs who governed the city in its heyday from 1289 to 1355, we found Ambrogio Lorenzetti's "Allegories of Good and Bad Government," three walls of paintings that portray how a city-state prospers or descends into chaos, depending on its rulers. The details of daily life in the Middle Ages are vivid and absorbing, especially those in the good government panels showing a thriving land with sowers, threshers and a peasant leading a fat pig to market. That, as it turned out, was about as much of the fair Tuscan countryside as we would see on the trip.

Both mornings at our hotel, bad weather overshadowed Siena the way Florence did in the 16th century.

But there were benefits, in this case focusing our attention on the artistic treasures in Siena's museums, many moved there from outdoor locations.

We spent hours in the medieval pilgrims' hospice Santa Maria della Scala, the Pinacoteca art museum, the Duomo Museum and, of course, the Duomo itself, a cathedral and artistic repository that, to my mind, rivals the Sistine Chapel.

Past the exquisite west facade, 52 marble paving stones designed by great artists between the 14th and 16th centuries tell biblical stories. Nicola Pisano's 13th-century pulpit, supported by stone lions that clutch lambs in their teeth, is near the high altar. On the left side of the nave, a door leads into Piccolomini Library, which has 16th-century frescoes by the Perugian master Pinturicchio. In vivid color, they tell the story of Sienese Pope Pius II, a diplomat, poet and man of the world.

Late in the afternoon as we stumbled out of the baptistery at the rear of the cathedral, Martha spied a store called Erboristeria Amaranthus. The narrow shop specializes in Tuscan scents, soaps and cosmetics. For the next 45 minutes, the clerk passed esoteric perfumey scents under our noses and explained their compositions. I bought a bar of pomegranate soap, Catherine de' Medici's favorite.

We also sampled Siena's rich cuisine, which featured sausages made from semi-wild cinta pigs, onion-flavored "cipollata" soup and skeins of "pici" pasta, a thick spaghetti.

Although many restaurants were closed until the summer season, we found Papei, a trattoria behind Palazzo Pubblico, where we attacked bowls of hearty minestrone and let the house red wine from Chianti flow.

Martha had rabbit stew, and I ordered a guinea fowl roasted with pine nuts and white beans. Dessert seemed out of the question until the waitress indulged us with "vin santo," a dessert wine popular in Tuscany.

We sat for a long time dunking biscotti into the sweet, dark nectar, discussing Siena out of season. There had been nothing pleasant about wandering around the cold, wet town.

But no summer day-tripper can experience the art of Siena as intimately as we did, receive an impromptu seminar on scent-making or linger after dinner in a restaurant not worrying about monopolizing the table. And, certainly, we saved money by traveling in the low-season.

Even bad weather couldn't dampen the trip. On the way back to Rome, we stopped in the hill town of Montepulciano about 50 miles southeast of Siena where the fabled hills of Tuscany poked through the fog like Tuscan islands in a magical sea.