The large main river of Thessaly, copious in flow throughout the year. With its many tributaries - in Pelasgiotis flowing from the north and in Thessaliotis primarily from the south - it irrigates almost all of Thessaly (Thessalia). Rising in the Pindus  some 5 km to the east of Metsovo, the P. flows through the two great plains of Thessaly in the north and, after a stretch of 227 km through the Tempe Valley, into the Thermaic Gulf. References: Hom. Il. 2,755; Hdt. 7,128f.