MNAC (Museu Nacional d'Art de Catalunya)

The Palau Nacional was built for the 1929 International Exposition as a temporary pavilion and then never came down. Today it houses the MNAC — the most important art museum in Catalonia and the place to come if you're going to see one museum in Barcelona that isn't a Gaudí site.

The Romanesque collection on the ground floor is what makes it world-class. In the early twentieth century the museum sent teams into the Pyrenees to rescue the painted apses of village churches — frescos from the 11th and 12th centuries that were peeling off the walls in remote valleys. They were stripped from the original walls using a now-extinct Italian technique called strappo and reinstalled inside replica apses in the museum so you can see them as the village congregations would have. The Pantocrator of Sant Climent de Taüll is the most famous single image, but the whole hall is unmatched in Europe.

The Gothic galleries that follow include early Catalan altarpieces; the upper floors hold Cambó's old-master donations (Velázquez, El Greco) and a strong 19th–20th-century Catalan collection with Casas, Rusiñol, and Fortuny — useful context if you've been looking at Gaudí buildings and wondering what the painters of that generation were doing.

The location is half the experience. The terrace in front of the museum looks straight down the Magic Fountain to Plaça d'Espanya — one of the best views in Barcelona, especially at sunset. Free for everyone on Saturdays after 3 PM and the first Sunday of each month, and the rooftop viewpoint is included with your ticket.