The Cares is a river in Northern Spain that flows through the autonomous communities of Asturias and León until it joins the Deva River and flows into the Atlantic Ocean at the Bay of Biscay. It forms the Tina Mayor estuary, the natural border between Asturias and Cantabria. The Cares is known because of the narrow and spectacular canyon it forms when passing the Picos de Europa. A trekking path, "Ruta del Cares", runs along the river. The stream is also known for the quality of its salmon. The Cares river is joined by the Deva river. Many companies rent kayaks to descend both rivers. Kayaking is popular here during the summer.