Housed in the former Casa del Conde de Jaruco, or “La Casona,” on the southwest corner of the square, and restored in 1979, the Galería La Casona exhibition space is devoted mainly to solo exhibitions, although it also includes catalogues of leading contemporary Cuban artists. A store and a gallery—Tienda de Ediciones Artísticas and Galería Diago—are also here, along with offices of the Fondo de Bienes Culturales.
Another fine example of early Baroque architecture, the building completed in 1737 closely resembles the Casa del Conde de Casa Lombillo in form, with magnificent mediopuntos atop the loggia. The ceilings are masterpieces of carpentry; the courtyard, portals and rooms are majestically large and are supported by interior arches with beautiful stained-glass windows. The mammoth carriage doors feature doorknockers in the form of an African slave woman with scarred cheeks.
The mansion was purchased by Gabriel Beltrán de Santa Cruz y Aranda in 1770 after receiving the title of Count of San Juan de Jaruco, from which the house takes its name, although the Count actually lived there briefly. After his death in 1772, the house was inherited by his cousin-wife Teresa Rita Beltrán de Santa Cruz y Calvo. The house was the birthplace of the notable writer and singer Dona Mercedes de Santa Cruz y Montalvo, afterwards Countess of Merlin, and a place of reunion of many illustrious visitors to Havana.