ওয়েবBuenos Aires ( / ˌbweɪnəs ˈɛəriːz / or /- ˈaɪrɪs /; [12] Spanish pronunciation: [ˈbwenos ˈajɾes] ⓘ ), [13] officially the Autonomous City of Buenos Aires, [a] is the capital and primate city of Argentina. The city is located on the western shore of the Río de la Plata, on South America's southeastern coast.