The Zêzere (Portuguese pronunciation: [ˈzezɨɾɨ], Spanish: Cécere [ˈθeθeɾe]) is a river in Portugal, tributary to the Tagus. It rises in the Serra da Estrela, near the Torre, the highest point of continental Portugal. The Zêzere runs through the town Manteigas, runs through Belmonte, passes south of the city of Covilhã and east of the town of Pedrogão Grande. It flows into the Tagus in Constância. It is the second longest river entirely within Portuguese territory (the Mondego being the longest). Its slope allows for the hydroelectric powerplants of Cabril, Bouçã and Castelo de Bode.
Beginning at the headwaters, there are 3 dams on the Zêzere: