The Plaça Sant Jaume is the political nerve center of Barcelona. Separated by a wide expanse of polished flagstones, the Casa de la Ciutat, home to the ajuntament (town hall), faces the Palau de la Generalitat, seat of Catalonia's autonomous government. The square itself frequently acts as a stage for protest gatherings, rowdy celebrations (such as when a local team wins a sporting event), and local traditions like the spectacular celebratory castellers (human towers) between mid-August and the end of October.

The buildings themselves are only infrequently open to the public, but if they are open when you are there, they are well worth visiting, especially the Palau de la Generalitat. Although the governing body of Catalonia has its origins in 1283 under the reign of Pere II, it wasn't until the 15th century that it was given a permanent home. The nucleus spreads out from the Pati de Tarongers (Courtyard of Orange Trees), an elegant interior patio with pink Renaissance columns topped with gargoyles of historical Catalan folkloric figures.

Another highlight is the Capella de Sant Jordi (Chapel of St. George), which is resplendent with furnishings and objects depicting the legend of Catalonia's patron saint, whose image is a recurring theme throughout the Generalitat. The walls of the Gilded Hall are covered with 17th-century Flemish tapestries.

Across the square is the late-14th-century Casa de la Ciutat, corridor of power of the ajuntament. Behind its neoclassical facade is a prime example of Gothic civil architecture in the Catalan Mediterranean style. The building has a splendid courtyard and staircase. Its major architectural highlights are the 15th-century Salón de Ciento (Room of the 100 Jurors), with gigantic arches supporting a beamed ceiling, and the black-marble Salón de las Crónicas (Room of the Chronicles). The murals here were painted in 1928 by Josep María Sert, the Catalan artist who went on to decorate the Rockefeller Center in New York.