The river Jalón (Latin: Salo) is located in the northeast of Spain, and is one of the principal tributaries of the Ebro.

The flow rate in Calatayud is 20.8 cubic metres per second (730 cu ft/s), but is highly irregular due to the great range of Mediterranean rainfall patterns.

The Jalón then meanders through the Paleozoic zones of the Cordillera Ibérica near Bubierca, being joined by the Piedra and the Manubles at Ateca.

At Calatayud, the river expands into a broad valley and is joined by the Jiloca, Perejiles and Ribota.

[4] According to E. Bascuas, "Jalón" is a form belonging to the old European hydronymy, and derived from the Indoeuropean root *sal- 'flowing water, stream'.