West of the harbor, the Monserrat neighborhood and its surrounding area are both the origin and the scenario of the country's political history. The city was built around the Plaza de Mayo which is bordered by the Cabildo - the government's cradle in the colonial period and currently a museum; the Casa Rosada - seat of the executive power; and the Metropolitan Cathedral, built in the XVIIIth century in the neo-classic style where the remains of General San Martin are kept.

Guarded by tall palm trees, the May Pyramid in the center of the square commemorates the 1810 revolution, and the surrounding buildings constitute a series of public buildings, ministries, offices and banks. Historically the square was a center for political demonstrations and as of 1977, during the military dictatorship, the "Madres de Plaza de Mayo" marched there every Thursday afternoon to demand information and justice regarding the fate of their missing loved ones. An attitude they maintain to this day because their demands remain unanswered.

A few blocks away, at the corner of Alsina and Defensa, it is worth visiting the Farmacia de la Estrella with its wooden entrance and health-related paintings. The City Museum operates on the first floor. Walking towards Bolivar Street, you arrive at the Manzana de las Luces, where you can visit defensive tunnels from the XVIIIth century, and the Saint Ignacio Church.

The Avenida de Mayo, which runs from the square, is reminiscent of Madrid's Gran Via with its splendid façades. Among these buildings is the legendary Cafe Tortoni. The avenue leads all the way to the Palacio del Congreso (the Palace of Congress) where national legislators convene throughout the year.