Colonists built the first town council chambers at Plaza Mayor (today’s Plaza de Mayo) in 1610. When Buenos Aires Cabildo became obsolete after 75 years, construction of its replacement dragged on throughout the 18th century. This was the capitol of the Viceroyalty of the Río de la Plata government until they were displaced during the May Revolution in 1810. Inside is a national museum dedicated to this turning point in the history of Buenos Aires and Argentina.
