This area southeast of the Ribeira Sacra area is an excellent destination to watch raptors and birds typical of Mediterranean environments. Visit the narrow valleys of the Sil's two tributaries: the Navea river, which begins in the mountains of O Invernadeiro, and the Bibei river which, while born in Sanabria (Zamora), runs its course almost entirely through the region of Viana. Rocky areas and scrub are found and, with some luck, a number of gems of the Galician bird population can be found.