It is the second largest exclusively Portuguese river, after the Mondego, and originates in Serra da Estrela.

The Bouçã dam is located next to the town of Bouçã and uses the flow of the Zêzere river. Construction ended in 1955.

Near Foz de Alge (Alge river) are the Fragas or Penhas de São Simão. In addition to the beautiful landscape that surrounds it, you can see, from here, the ruins of blacksmiths, dating back to the 18th century.