This is where the source of the Zêzere river is, Serra da EsTRELA, in the shadow of the Torre mountain at an altitude of around 1993 m. It drops down from here through steep cliff walls and starts to take form in Covão d´Ametade, a paradisaical backdrop full of bucolic and poetic sentiment. Leaving Covão d'Ametade behind, the river Zêzere bursts through the glacial valley and travels 248 km through abundantly fertile valleys, before flowing out into the River Tagus at Constância. With a length of over 10 km, the Zêzere glacial valley has a well moulded U-shape, oozing water from all of its pores.