Timok is a river located in southeastern Serbia and Bulgaria. It flows through the Timok Valley and is known for its picturesque landscapes and rich biodiversity. The river is approximately 100 kilometers long and is a tributary of the Danube River, contributing to the region's water system. The Timok region is also notable for its historical significance, with archaeological sites that date back to ancient times. The area has been inhabited by various cultures, including the Thracians and Romans, making it a point of interest for historians and tourists alike.