Viana
Viana is a small town and region located in Navarre, Northen Spain. It is where the Siege of Viana took place, and is also where Cesare Borgia fought and died during the siege of the castle. He was later buried there as well.
Assassin's Creed: Brotherhood
King John III of Navarre ordered his brother-in-law Cesare Borgia to lead his 10,000 to Viana and retake the Viana Castel from Count of Lerin. Ezio Auditore, now Grand Master of the Assassin Order, travels to Viana to kill Cesare Borgia once and for all. In 1507, the year Cesare died at the Siege of Viana, Ezio and Cesare will finally confront each other for their first and last battle with each other. This is the location where Ezio finally gets revenge. Cesare states " No man can kill me" and then Ezio replies "Then fate will" then there for letting him plummet to his death.Like Arsuf in Assassin's Creed and Rome in Assassin's Creed II, the player cannot return to Viana after they complete the mission, however the mission can be replayed returning to Viana.