Saint-Brieuc is a French commune located in Brittany, in western France. It is the prefecture of Côtes-d'Armor, it is also the most populated city with a population of more than 45,000 inhabitants (2015) called the Briochins and Briochines. With 171,721 inhabitants (2013), the Briochine urban area is the most populated in the department. The city is famous because it is crossed by two valleys where two rivers flow: Gouët and Gouédic.