The building stands over a pagan temple dedicated to the goddess Minerva. Construction of the existing Duomo started in 1200, with the main sections already completed by 1215. The dome was built between 1259 and 1264. The Latin cross design of the church includes three naves and is entirely sheathed in strips of alternating black and white marble, a reference to the black and white colours of the coat of arms of the city of Siena. The lower section of the facade was built between 1284 and 1296, probably under the supervision of Giovanni Pisano. In 1317 work was started on the extension towards the area known today as the “Valle Piatta’. The building of the Duomo in the Thirteenth century shows the new architectonic concept in the edification of the great churches, while the rebuilding of the XIV century shows the will to make a more majestic cathedral.
One of the most suggestive work is undoubtedly the floor whose tarsias had been realized with various tecniques in various periods since 1379 to 1550 representing the man's history and his looking for the safety; in addition to the floor, the central granite column also deserves to be noticed of Nicola Pisano's pulpit on a sculptural group.