Badalona is a city in eastern Catalonia. It is located in the comarca of the Barcelonès, joined to Barcelona and part of its metropolitan area. It is situated on the left bank of the small Besòs River and on the Mediterranean Sea, backed by the Serra de la Marina mountain range. Badalona is the third most-populated municipality in Catalonia after Barcelona and L'Hospitalet de Llobregat. It became a city in 1897.