The Cathedral of Notre-Dame of Paris is one of the most beautiful architectural constructs of the 12th century. Maurice de Sully began the construction in 1163. Demolished and restored, one tower after another, the cathedral represents a curious example of Saxon-Gothic and Greco-Roman art. Every façade, each stone of this old church, is a page in the history of not only France but also of science and art. The cathedral has three gates, each decorated with magnificent sculptures depicting stories from the Bible. The beautiful statue of the Virgin Mary dates from the end of the 13th century. It is one of the very rare remains of the original statuary of Notre-Dame. The Red Door, appropriately named for its color, was constructed in 1270. Right above the gates, there is the gallery of kings. The cathedral is framed by two grand towers at the corners. They are almost identical, except the one on the north is slight larger, with better executed details, and is overall more finished. The four facades of the towers are surrounded by gargoyles, overlooking a magnificent view of Paris. The backside of the cathedral is just as impressive. The stained glass window, 13 meters in diameter, is a masterpiece of design and execution. The vault is also a highlight (many more architectural details).