Iguazu falls map. Below its confluence with the San Antonio River, the Iguazu River forms the border between Argentina and Brazil. Number of drops: 275. Longest drop: 82 metres (269 ft). Argentina Location: Misiones Province. Brazil Location: Paraná State. Coordinates: 25°41′12″S 54°26′41″W | Coordinates: 25°41′12″S 54°26′41″W . Image by KimKim