The Uruguay River forms the border between Uruguay & Argentina & most of the border between Argentina & this country
Unlike most other countries, the Guaran language is still spoken 
by 90... [DOC] [TLE] July 25, 2013 - Southeastern South America - MODIS Web - NASA [PAR] Jul 25, 2013 ... Part of the border between Uruguay and Argentina, the shores of the Rio de la 
Plata are the most densely populated regions in each country.