were still not completed; the south tower was not completed until the second half of the 15th century. This promptness in completion gives the cathedral a great unity of architectural style. The León Cathedral was inspired by the layout of the Reims Cathedral (although it was smaller in area size), which was well known to Master Enrique. Like most French cathedrals, León was constructed with modular geometry based on the triangle (ad triangulum), whose members related to the square root of 3, to which the totality of its parts and the whole respond. This aspect, like the plan, the elevations, and the decorative and symbolic repertoires, convert the cathedral into an authentic trans-Pyrenees building, away from the Hispanic current, which has earned it the qualifications of “the most French of Spanish cathedrals,” or the Pulchra Leonina. In addition to its layout, the Cathedral of Leon is also inspired by that of Rheims in its structure, the form of the chapels of its ambulatory (in this case polygonal), and the development of its transept. The influence of Chartres Cathedral can be seen in the western porch. The one in Leon abandons the model of Rheims Cathedral in the elevations beyond the body of the clerestory, as it is transparent there and it accommodates the technical progress achieved in the Sainte Chapelle in Paris and Amiens Cathedral. French influence is also found in developing the chancel, where initially the choir was to be put according to their custom. Specifically Leonese is the location of the cloister, with no organic tie to the temple, the exit in the floor plan of the towers of the main façade, displaying the elevation of the buttresses of the nave, and the discontinuity of the five naves at the front end of the main area of the temple, which were reduced to three. The problem was that a major part of the site sits upon Roman remains, hypocaust of the second century, which complicated the foundation of the pillars. The accumulation of moisture and water leakage caused serious problems for the master builders. Besides that, most of the stones were of mediocre quality, a type of limestone, with little resistance to atmospheric agents. Furthermore, the subtlety of its style was a challenge to its material; its numerous supports were extremely fragile, the lines are reduced to total optimization, in such a way that various architects of the