This group of four buildings set around a 16C Mudéjar patio is home to the cathedral museum, which displays objects, garments and various liturgical documents, including a letter signed by St Teresa of Ávila. Note in particular the monstrances: Custodia del Cogollo (16C), Custodia de Ana de Viya (neo-Gothic) and, in particular, the Custodia del Millón (18C), said to contain a million precious stones.