Río Nalón is a river located in the northern region of Spain, specifically in the Asturias province. It is one of the longest rivers in the area, flowing approximately 113 kilometers. The river originates in the Picos de Europa mountains and eventually empties into the Cantabrian Sea. The Río Nalón is known for its scenic beauty and ecological importance. It passes through several towns, including Langreo and San Martín del Rey Aurelio, providing water for agriculture and supporting local wildlife. The river also offers recreational activities such as fishing and kayaking, attracting both locals and tourists.