The Porcía and Mazo Rivers pass through the municipality.
History
Artifacts from the Neolithic Age indicate an early settlement of the region. The remains of hillforts are visible, in Arancedo as well as in neighbouring Coaña and Mohias. In the 18th century, the gold mines, which are still in use, were found near the embankment castle of Arancedo. During the Middle Ages, El Franco was split between the Lugo and Oviedo dioceses, and the administrative capital was in Castropol. In 1852, the administrative seat was moved to El Franco in the parish of A Caridá.
The top industries are livestock and fishery. The milk industry had the highest growth, after preventive measures of the EU started to affect the fishing industry. The tourism industry and administrative companies form the second largest sector of the economy and tourism has the biggest growth of the region. Smaller commercial companies and production companies are found predominantly in the small industrial parks of the adjoining municipality.