The Gerês Mountain has five major water courses, tributaries of the Cávado river. One of them, flowing from north to south, is the Toco river.

The longest river in the Iberian Peninsula, with 1009 kilometres. It starts in Spain, more precisely in Albarracim, at an altitude of 1593 metres, and flows to the Atlantic Ocean. Its estuary has around 262 sqaure kilometres, in the area of São Julião da Barra. It borders Spain in an extension of 50 kilometres. It has several tributaries, which lends it specificity and beauty.

The largest river of the Iberian Peninsula. It has its spring in Spain and its mouth on the Atlantic Ocean, in Lisbon, Portugal.

Starting to the north of the São Mamede Hill, this river separates Portugal and Spain and totals 40 kilometres, a part of which are shared by both countries. It is one of the main rivers in the north of the Alentejo region that flows to the Tagus and one of the main tributaries of its left bank.

A tributary of the Tagus river right bank that starts on the Gardunha Hill, at an altitude of 1227 metres, in Castelo Branco. It has an estuary with 83 km and its mouth at Vila Velha de Rodão.

A small river, with crystal clear waters, that flows to the Minho river.

A tributary of the Cávado river with a length of 37 km and an area of 257 km2. It has its spring on the Gerês mountain and includes the Vilarinho das Furnas dam, with a used capacity of its reservoir of 69.7 hhm3.

This river starts in Spain, on the Ruidera lagoons, at Ciudad Real, crosses Portugal and has its mouth on the Atlantic Ocean, between the Portuguese town of Vila Real de Santo António and the Spanish town of Ayamonte.

The Gerês Mountain has five major water courses, all tributaries of the Cávado river. The Gerês river is one of them, flowing from north to south.

The Gerês Mountain has five major water courses, all tributaries of the Càvado river. The rio do Forno (Oven river) is one of them and flows from north to south.