Tributaries include the Tiete and the Iguacu, while its Guaira Falls were completely submerged by the Itaipu Dam. It forms south of Brasilia, where a similarly named river joins the Rio Grande rivers.  It then flows southwest, and forms the southern border of Paraguay.  After a stretch in Argentina, it merges with the Urugu
Tributaries include the Tiete and the Iguacu, while its Guaira Falls were completely submerged by the Itaipu Dam. It forms south of Brasilia, where a similarly named river joins the Rio Grande rivers.  It then flows southwest, and forms the southern border of Paraguay.  After a stretch in Argentina, it merges with the Uruguay River, and flows through Buenos Aires into the Rio de la Plata.  FTP, name this South American river, whose name might be confused with that of a vicious fish.
Tributaries include the Tiete and the Iguacu, while its Guaira Falls were completely submerged by the Itaipu Dam.
Parana River