The broad plaza facing Argentina's national legislature is the political counterpoint to Plaza de Mayo — less ceremonial, more combative. Demonstrations, strikes, and marches have been staged here for over a century, and the open space allows crowds of considerable size to assemble.
The Palacio del Congreso on the west side is a massive Beaux-Arts building completed in 1906, modelled loosely on the Capitol building in Washington. Free tours of the interior run on weekdays; the library and the main debating chambers are open to visitors. The fountain in the plaza's centre — the Monumental Fountain — was designed by Jules Lagae and is decorated with allegorical figures representing the rivers of Argentina.