The most impressive part of Turin's 15th-century cathedral is the shadowy black marble–walled Cappella della Sacra Sindone (Chapel of the Holy Shroud), where the famous relic was housed before a fire in 1997. The chapel was designed by the priest and architect Guarino Guarini (1604–83), a genius of the baroque style who was official engineer and mathematician to the court of Duke Carlo Emanuele II of Savoy. The fire caused severe structural damage, and the chapel is closed indefinitely while restoration work proceeds.
The Sacra Sindone is a 4-yard-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, bolstering both sides of the argument. On one hand, three separate university teams—in Switzerland, Britain, and the United States—have concluded, as a result of carbon 14 dating, 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, which resembles a photographic negative, and how they could have had the knowledge or means to incorporate traces of Roman coins covering the eyelids and endemic Middle Eastern pollen woven into the cloth. Either way, the shroud continues to be revered as a holy relic, exhibited to the public on very rare occasions. At other times, it is preserved in a sealed casket in the left aisle of the cathedral. In lieu of the real thing, a photocopy is on permanent display nearby.