Between the head of the cathedral of Santiago de Compostela and the Plaza del Obradoiro, exist a slope that Master Mateo decided to save by building a crypt, something unprecedented in Galicia in that time. The space is organized by a large pillar with eight attached columns from which the arches of the vaults emerge, and which is just under the mullion of the Portico. In addition, its plant imitates the one of the cathedral, what can be observed in the five chapels, which are around the ambulatory. The central one follows the model of the chapel of the Savior.