Introduction to the Manzanares River: The Manzanares River is the star of many famous painters' paintings. It is 92 kilometers long and finally flows into the Jarama River. There is a Segovia Bridge (Puente de Segovia) on the river, which is the oldest bridge in Madrid and was built in the 16th century. The bridge is the best place to view the Royal Palace and Almudena Cathedral.