The Aragon River is a major tributary of the Ebro. Other popular tributaries like the Veral and Aragon Subordán
were the scene of the World Fly Absolute Salmonid 2003 championship. The Yesa Reservoir located in the lower middle part of the river sets the border with
the Navarre region. When its waters sink a great little hidden treasure comes to light: the hot springs of the old village of Yesa. This usually occurs in late autumn
and it is an ideal time to go for a swim. The river Aragon runs, upstream of reservoir Yesa, parallel to the Pyrenees, following what is known as Canal
Berdún or Bal Ancha.