Manzanares (river) protected as the "Parque Regional de la Cuenca Alta del Manzanares", a nature reserve which is recognised as a biosphere reserve by UNESCO. The Manzanares flows in a south-eastern direction from its source, and passes through the medieval town of Manzanares el Real where it is dammed to form the Santillana reservoir, one of the most important water supplies for the capital. The river then takes a southern direction and enters the Monte del Pardo, an ecologically valuable area on the edge of Madrid. The river is canalised where it passes through the built-up areas of the city. As at
Grejs River Grejs River Grejs River () is an approximately river in Vejle Municipality in Denmark. Its source is Fårup Lake, south of the village of Jelling. It starts by heading east through a tunnel valley, then turns south to run through Grejs Valley (), the largest gorge in Denmark, until it reaches the city of Vejle. North of Vejle, it splits into two branches, Omløbsåen ("Bypass River") and Mølleåen ("Mill River"). Omløbsåen runs west around the city centre to meet Vejle River, while Mølleåen flows through the city and empties into Vejle River just south of the city centre. A section