The ambulatory is surrounded with a triforium. It contains nine side chapels and five large, richly decorated panels with reliefs (attributed to Lucas Giraldo and Vasco dela Zarza). The middle panel is an alabaster piece, with a wealth of detail and structured like a retable, by Vasco de la Zarza and accommodates the tomb of Alonso de Madrigal, also named "El Tostado", a bishop of Ávila. The cathedral museum, located in the sacristies, houses a large number of works of art, among which the portrait of the knight Don Garci Báñez de Muxica by El Greco and the chalice and paten of Saint Secundus. But it most notable work is the enormous processional monstrance (1571), a shrine in six bodies by the goldsmith Juan de Arphe y Villafañe. Its main theme is the "Sacrifice of Isaac".