Built by order of the Catholic Monarchs next to the Mezquita Mayor (Great Mosque), its construction was started at the beginning of the 16th century by Enrique Egas but soon passed over to Diego de Siloé, who designed what is considered to be the masterpiece of the Spanish Renaissance. The main façade is a superb Baroque creation by Alonso Cano, with the bell tower at one end. Inside, windows brought from Flanders crown the walls of the Capilla Mayor (Main Chapel) and the soft light filtering through them illuminates two of the cathedral’s main treasures: the Crucifix by Martínez Montañés in the sacristy and, underneath, Alonso Cano’s Immaculate Conception.