The Bouches-du-Rhône is one of several administrative "departments" in the south of France. It is situated within the French "region" of Provence-Alpes-Côte d'Azur.
The city of Marseille is the capital of both the Bouches-du-Rhône department and the Provence-Alpes-Côte d'Azur region. Bouches-du-Rhône means "mouth of the Rhone" in English.