 Cardinal Astorga y Céspedes is buried at the feet of "El Transparente".According to American writer James Michener's book "Iberia" (1968), the "Transparente" was installed to allow light to pass from the ambulatory behind the high altar (or 'reredos' as he calls it), onto the tabernacle (container for the Blessed Sacrament) which stayed in constant shadow because of the tall reredos.Not only was a skylight cut into the top of the thick back wall of the cathedral across the ambulatory behind the high altar, but another hole was cut into the high altar itself to allow the shafts of sunlight to illuminate the tabernacle like a spotlight.