The museum occupies the old Pazo de Quiñones de León, from the 17th century and remodelled at the end of 19th century. The building is an example of the majestic architecture of Galicia. It is surrounded by the gardens designed in 1890 by Portuguese Jacinto de Matos.
The museum was opened in 1937. On the one hand, Fernando Quiñones donated in 1925 the gardens and pazo; on the other hand Policarpo Sanz legacy were included in the museum. The museum pivots around 29 halls with a library and a permanent exhibition. The ground floor has kept the atmosphere of the old residence of the donors of the pazo. This floor shows European paintings from 17th and 18th centuries - all donated by Policarpo Sanz.
The archaeology section is displayed in the adjoining building. Two halls showcase the evolution of Vigo and outskirts since the Palaeolithic to the Middle Ages and the finding the excavations of the Mount Castro. The section of Galician art shows a tour through Galician painting and sculpture, ranging from the end of 19th century up to today, depicting the main trends and artists.