The village of A Ponte is the beginning and end of this circular mountain trail. The tour begins in front of the Church of Santa María Madalena and passes next to the old school-house, which has been converted into the ZEC Pena Trevinca Visitor Centre. Immediately, the path forks: the path ahead of you leads to a climb up O Fial mountain and Lagoa da Serpe (Serpent Lagoon) while the path to the right is lighter and leads first to Lagoa de Ocelo.

Choosing the latter, the route ascends until it reaches the metal fence of the Xares Game Reserve. The wide track continues to Lagoa de Ocelo (1,510 m). Then, a narrow mountain path heading east that skirts the foot of O Fial mountain reaches the Lagoa da Serpe, which is related to various legends.

To return, carry on walking uphill along a steep path to a magnificent viewpoint over the lagoon itself. The route follows some tracks that allow you to easily reach the rounded summit of O Fial (1,841 m), a place from which the entire Sierra de Trevinca and the valleys of Xares and Bibei can be seen. Descend to A Ponte via the Pena Ferro track and the As Calellas road.