El Palacio del Buen Retiro in Madrid was a large 17th century palace complex ordered by Philip IV as a secondary residence and place of recreation (hence its name). Today what little remains of its buildings (the Salón de Reinos & the Casón) and gardens forms the Retiro Park.
The Casón del Buen Retiro is one of the two buildings saved from the Palacio del Buen Retiro, as the Salón de Baile (the ballroom). The ceiling of the main room is decorated by a fresco by Luca Giordano (c. 1697) for Charles II, depicting The Apotheosis of the Spanish Monarchy.
It is now an annex of the Museo del Prado.