The Besòs River is a river in northeastern Spain, flowing through the Catalonia region. It originates in the Collserola Natural Park and travels approximately 11 kilometers before emptying into the Mediterranean Sea near the city of Barcelona. The river serves as a natural boundary between the cities of Barcelona and Badalona. Historically, the Besòs River has faced pollution and environmental challenges due to urban development. Efforts have been made to restore its ecosystem and improve water quality, making it a focus for local conservation initiatives. The river is also a popular spot for recreational activities, including walking and cycling along its banks.