The Cathedral of Siena preserves numerous masterpieces from every era. One exceptional work, visible only during certain periods of the year, is the Floor, described as “the most beautiful, grand, and magnificent ever made” by Giorgio Vasari. It is the result of a program realized over the centuries, from the 14th to the 19th century. The preparatory cartoons for the fifty-six marble inlays were provided by important artists, all Sienese except for the Umbrian painter Bernardino di Betto, known as Pinturicchio, who created the inlay depicting the Monte della Sapienza in 1505. The technique used to transfer the ideas of various artists onto the floor is that of marble inlay and graffito. It began simply, gradually achieving surprising perfection: the first inlays were traced on slabs of white marble with grooves made by chisel and drill, filled with black stucco. This technique is called graffito. Then colored marbles were added, juxtaposed together as in a wooden inlay: this technique is called marble inlay.
Complesso Monumentale del Duomo di Siena also includes a series of monuments among the most significant in the European artistic panorama. Inside the Cathedral, there is a suggestive and grandiose decoration by artists such as Nicola Pisano, Donatello, Michelangelo, Bernini, and Pinturicchio. Also part of the complex are the Crypt, with a splendid cycle of frescoes from the late 13th century, and the Baptistery, with the monumental baptismal font, the ultimate expression of Renaissance sculpture, with bas-reliefs created by Jacopo della Quercia, Lorenzo Ghiberti, and Donatello. The visit concludes with the Opera Museum, famous above all for the extraordinary collection of marble sculptures carved by Giovanni Pisano and for the large altarpiece with the Maestà (1308-1311) by Duccio di Buoninsegna. From the Museum, ascending along the spiral staircase of the unfinished facade of the “Duomo Nuovo”, it is possible to admire the most fascinating panorama of the city and the surrounding landscape.