8 Best Sights in Piedmont and the Valle d'Aosta, Italy

To reach the church—built between 983 and 987 AD, and which inspired Umberto Eco to write The Name of the Rose—you must climb 150 steps from the Porta dello Zodiaco, a splendid Romanesque doorway decorated with the signs of the zodiac. On the left side of the interior are 16th-century frescoes representing New Testament themes; on the right are depictions of the founding of the church.

Aosta's cathedral dates from the 10th century, but all that remains from that period are the bell towers. The decoration inside is primarily Gothic, but the main attraction of the cathedral predates that era by 1,000 years: among the many ornate objects housed in the treasury museum is a carved ivory diptych from AD 406 portraying the Roman emperor Honorius. You can also see frescoes dating from the 11th century above the Gothic vaults. The treasury and frescoes can only be visited on weekends between 3 and 5:30 pm, or with advance reservation on weekdays.

This Gothic church is dedicated to Asti's patron saint, believed by some to have been decapitated by the Emperor Hadrian on this very spot. San Secondo is also the patron of the city's favorite folklore and sporting event, the annual Palio di Asti, a colorful medieval-style horse race that's similar to Siena's. It's held each year on a Sunday in early September in the vast Campo del Palio to the south of the church.

Originally there was a 6th-century chapel on this site, founded by the Archdeacon Orso, a local saint. Most of the structure was destroyed or hidden when an 11th-century church was erected over it. If you go up the stairs on the left from the main church you can see the frescoes of Christ and the apostles (ask the sacristan, who'll let you in). Take the outside doorway to see the church's crowning glory, its 12th-century cloister, enclosed by some 40 stone columns with carved capitals depicting scenes from the life of St. Orso.

Dedicated to the Assumption of the Virgin, the Duomo is an object lesson in Italian Gothic architecture. Completed in the early 14th century, it is decorated so as to emphasize geometry and verticality: pointed arches and narrow vaults are completely covered with frescoes that direct your gaze upward. The porch on the south side of the cathedral facing the square was built in 1470; it represents the Gothic style at its most florid and excessive.

The most impressive part of Turin's 15th-century cathedral is the Cappella della Sacra Sindone (Chapel of the Holy Shroud), where the famous relic is housed in a sealed casket. The Sacra Sindone is a 12-foot-long sheet of linen, thought by millions to be the burial shroud of Christ, bearing the light imprint of his crucified body. The shroud first made an appearance around the middle of the 15th century, when it was presented to Ludovico of Savoy in Chambéry. In 1578 it was brought to Turin by another member of the Savoy royal family, Duke Emanuele Filiberto.

It was only in the 1990s that the Catholic Church began allowing rigorous scientific study of the shroud. Not surprisingly, the results have been hazy. On one hand, three separate university teams—in Switzerland, Britain, and the United States—have concluded, as a result of carbon-14 analysis, that the cloth dates from between 1260 and 1390. On the other hand, they are unable to explain how medieval forgers could have created the shroud's image. Either way, the shroud continues to be revered as a holy relic, exhibited to the public on very rare occasions.

On the east bank of the Po, this neoclassical church is modeled after the Pantheon in Rome. It was built between 1827 and 1831 to commemorate the return of the house of Savoy to Turin after the fall of Napoléon's empire.

Architect, priest, and mathematician Guarino Guarini was in his mid-sixties when he began this church in 1668. The masterful use of geometric forms and the theatrical control of light and shadow show him working at his mature and confident best. Stand in the center of the church and look up into the cupola to appreciate the full effect.