The Tuela River between two mountain ranges Nature · Lubián, Sanabria, Zamora Image of Lubián, not of the place itself. The Tuela and its tributaries, the río Pedro and the río Leira, cross a municipal district wedged between the Sierra Segundera to the north and the Sierra Gamoneda to the south, with barely 3.13 inhabitants per square kilometre. Photo: Estevoaei (CC BY-SA 4.0) What to see and do in Lubián