The Nativity façade is the unique part of the temple directly built by Gaudí.
When Gaudí died in 1926 only the tower of San Barnabas was totally finished and the other three very much advanced.It is formed as the other façades by four bell towers of square plant in its base, that comes to be a cylindrical structure when arrived at one fourth of their height. Further up, they come to a parabolic profile to become a pinnacle that crown each one of the towers. The three spaces remaining among the edges, are take up by three entries forming the portico.Totally accessible through spiral stairs leaving an important central empty space and catching up to the top. All the length of the bell towers is opened through a sort of stone blinds allowing the tubular bells sound diffusion planed by Gaudí. The silhouette of the upper part resembles a Bishop's staff. Other symbols to see, are the knot symbol of the bishop's ring and in the culmination a golden cross showing the capital letters of the apostle to whom the tower is dedicated.