MNAC (Museu Nacional d'Art de Catalunya) provides a dizzying overview of Catalan art from the 12th to the 20th centuries. The Gothic collection is also excellent and starts with some late 13th-century frescoes that were discovered in 1961 and 1997, when two palaces in the city were being renovated.
MNAC (Museu Nacional d'Art de Catalunya) is divided into sections according to time periods, making it possible to see only the areas you wish to check out. There are also frequent special events held at the Museu Nacional d'Art de Catalunya, to which entrance is often free. These include lectures, specialized exhibits and films.