The Palau was originally the Spanish Pavilion at the World Fair of 1929. After extensive renovation work it was reopened in 1997. Overall, the museum exhibits more than 260,000 works of art and is therefore the largest and most important museum in Barcelona.

A Catalan Museum Act, the museum MNAC was founded in 1990 by the merger of the Museu d'Art de Catalunya (Romance, Gothic, Renaissance and Baroque) and the Museu d'Art Modern (Arts of the 19th and 20th century).

The most world's largest collection of Roman frescoes fills most of the rooms of the MNAC. The Romanesque frescoes date from the vestibule of 29 major Romanesque churches in the Pyrenees. So they could be saved before being destroyed by the Spanish Civil War. The frescoes are in so-called "ambits'. These are small demarcated areas. In each ambit is information about the church, from which the frescoes are. In addition, the MNAC shows countless sacred objects.

The MNAC has the most important collection of Catalan art from the 19th Century and the first decades of the 20th Century. Several phases of art history changed in this time: neoclassicism, realism, modernism (Catalan Art Nouveau).

In addition to the Roman frescoes in the MNAC is located a department of Gothic frescoes and statues, a smaller collection is devoted to works of the Baroque and the Renaissance.

The Numismático Gabinete de Cataluña (GNC), the most important public collection of coins, a total of 130,000 units, 6 Century BC to tdate and 7800 pieces will be issued.

In the restored National Palau you also find changing exhibitions.