The façade of Siena Cathedral is one of the most fascinating in all of Italy and certainly one of the most impressive features in Siena. Each of the cardinal points (west, east, north, and south) has their own distinct work; by far the most impressive of these is the west façade. Acting as the main entryway to the Duomo proper, it boasts three portals (see Portal (architecture)); the central one is capped by a bronze-work sun. Built in two stages and combining elements of French Gothic, Tuscan Romanesque architecture, and Classical architecture, the west façade is a beautiful example of Sienanise workmanship. Work began on the lower part around 1284. Built using polychrome marble, the work was overseen by Giovanni Pisano whose work on the Duomo's façade and pulpit was influenced by his father Nicola Pisano. The lower portion of the façade is designed from Giovanni's original plans. Built in Tuscan Romanesque style it emphasizes a horizontal unity of the area around the portals at the expense of the vertical bay divisions. The three portals, surmounted by lunettes, are based on Giovanni Pisano's original designs, as are much of the sculpture and orientation surrounding the entrances. The areas around and above the doors, as well as the columns between the portals, are richly decorated with acanthus scrolls, allegorical figures and biblical scenes. Giovanni Pisano was able to oversee his work until about 1296 when he abruptly left Siena, reportedly over creative differences with the Opera del Duomo, the group that oversaw the construction and maintenance of the Siena cathedrals. Pisano's work on the lower façade was continued under the direction of Camino di Crescentino, but a number of changes were made to the original plan. These included raising the façade due to the raising of the nave of the church and the instillation of a larger rose window based on designs by Duccio di Buoninsegna and commissioned by the city of Siena. Work on the west façade came to an abrupt end in 1317 when the Opera del Duomo redirected all efforts to the east façade.