Its source is near the town of Reinosa in the Cordillera Cantabrica, and its tributaries include the Jalon [hah-LONE], Guadalope, and the Arga, which flows through a city known in Basque as Iru?.  
The city of Amposta, now located inland, was once a Roman port located on this river.  One of the most notable features of this river is the Mequinenza [meh-key-NEN-thaw] Reservoir, and to the northeast of the cape at which it meets the sea is the Gulf of San Jorge.  Its source is near the town of Reinosa in the Cordillera Cantabrica, and its tributaries include the Jalon [hah-LONE], Guadalope, and the Arga, which flows through a city known in Basque as Iru?.  It flows through cities such as Tudela and Logro? on its way to the sea at the Cabo de Tortosas.  The Gallego River branches off to the north at the location of the most famous city on its banks, Zaragoza.  FTP name this Spanish river, whose name may derive from the Basque word for "valley" or from the name of the inhabitants of the namesake peninsula.
The city of Amposta, now located inland, was once a Roman port located on this river.  
Ebro River (accept Ebre or Iberus)