The Museo del Prado - Casón del Buen Retiro is an extension of the Museo Nacional del Prado, located in the Barrio de las Letras. It is housed in a former royal palace and showcases a collection of 19th-century art. The museum features works by Spanish artists such as Sorolla, Fortuny, and Madrazo. Visitors can explore the galleries and admire the collection of paintings, sculptures, and decorative arts from the 19th century. The museum also hosts temporary exhibitions and cultural events.