In the inside walls there are also two chapels on either side which are known as the Chapels of Alabaster since they were built with that material. Those of La Inmaculada and of La Encarnacion are ascribed to Juan Gil de Hontañon and were built as from 1515. Those of La Virgen de la Estrella and of San Gregorio must have been begun by Juan Gil de Hontañon who is basically responsible for the exterior, and as from 1529 they were finished by Diego de Riaño, an architect who designed the architecture of the structure inside. The sculptures adorning these chapels were carved with the help of the French sculptor Nicolás de León.