Fill in the Blanks SPAIN'S RIVERSOnline version Let's review some features of the Spanish rivers. by Aguasantas Cano 1 Miño Watershed Guadiana rias Ebro Spain Mediterranean Tagus Watershed Watershed Atlantic Cantabrian We divide the rivers in Spain into three groups : the rivers of the , the rivers of the and the rivers of the . The is the longest river in the Iberian Peninsula . The is the longest river that is completely within Spain . The forms part of the border between and Portugal ; the forms another part of this border . In northern Spain there are drowned river valleys called .