La Sagrada Familia, the Nativity Facade
“Constructed between 1894 and 1930, the Nativity façade was the first façade to be completed. Dedicated to the birth of Jesus, it is decorated with scenes reminiscent of elements of life. Characteristic of Gaudí’s naturalistic style, the sculptures are ornately arranged and decorated with scenes and images from nature, each a symbol in their own manner. For instance, the three porticos are separated by two large columns, and at the base of each lies a turtle or a tortoise (one to represent the land and the other the sea; each are symbols of time as something set in stone and unchangeable). In contrast to the figures of turtles and their symbolism, two chameleons can be found at either side of the façade, and are symbolic of change.
The façade faces the rising sun to the northeast, a symbol for the birth of Christ. It is divided into three porticos, each of which represents a theological virtue (Hope, Faith and Charity). The Tree of Life rises above the door of Jesus in the portico of Charity. Four towers complete the façade and are each dedicated to a Saint (Matthias the Apostle, Saint Barnabas, Jude the Apostle, and Simon the Zealot).
Gaudí chose this façade to embody the structure and decoration of the whole church. He was well aware that he would not finish the church and that he would need to set an artistic and architectural example for others to follow. He also chose for this façade to be the first on which to begin construction and for it to be, in his opinion, the most attractive and accessible to the public. He believed that if he had begun construction with the Passion Façade, one that would be hard and bare (as if made of bones), before the Nativity Façade, people would have withdrawn at the sight of it.” – from Wikipedia.