The river Jalón (Latin: Salo) is located in the northeast of Spain, and is one of the principal tributaries of the Ebro. It has a length of 224 km and drains a basin of 9,338 square kilometresm. The flow rate in Calatayud is 20.8 cubic metres per secondm, but is highly irregular due to the great range of Mediterranean rainfall patterns.
The course of the river forms the main communication route between the Castilian Plateau and the Ebro. Until the late twentieth century, roads and railways between Madrid and Zaragoza followed this path.
