Argentina is also subdivided.
Argentina . With a mainland area of 2780400 km2 , Argentina is the eighth-largest country in the world , the second largest in Latin America , and the largest Spanish-speaking one . The country is subdivided into twenty-three provinces ( provincias , singular provincia ) and one autonomous city ( ciudad autónoma ) , Buenos Aires , which is the federal capital of the nation ( [ Capital Federal , links = no ] ) as decided by Congress . The declaration and fight for independence ( 1810 -- 1818 ) was followed by an extended civil war that lasted until 1861 , culminating in the country 's reorganization as a federation of provinces with Buenos Aires as its capital city . It is also a founding member of the United Nations , World Bank , World Trade Organization , Mercosur , Union of South American Nations , Community of Latin American and Caribbean States and the Organization of Ibero-American States . A sestiere ( plural : sestieri ) is a subdivision of certain Italian towns and cities .