• The Trancoso river is a natural border between Galicia (municipality of Padrendra) and Portugal (municipality of Melgaço).It has an excellent status of ecological quality and its banks are well preserved, so, in the Spanish and Portuguese hydrological plans, it has been proposed that they be Nature River Reserves.
• Location: It is a tributary of the Miño river and runs along the northwestern edge of the continental SCI (site of community importance) of Limia Baixa. It is also the boundary between the municipalities of Padrenda (Ourense, Galicia) and Melgaço (Viana do Castelo district).
• River Length: 13,6 Km
• Basin surface: 1.803,31 hª