- Cangas del Narcea, Ibias Western Asturias
- Maximum elevation: 1.100 m.
The bottom of the basins is a bed of quartzite stones and sands, with an abundance of pollen on the surface and leaves and moss around the edges, while the Peña Velosa basin has a quartzite stone substrate covered with brown humus, which gives a dark tone to the whole. Aveizuna is a lagoon located at the foot of the Bobia Teleyerba.
Plant life
Apart from the algae, both floating and attached to the stones, that exist in the four lagoons, in the lower lagoon there is a species of sparganium and a cyanophycean alga of the genus Batrachospermun. In an area of the desiccated banks of the Grande lagoon, bulbous reed grows, although in very small quantities.
As for Peña Velosa, the vegetation is similar to that of the Lagunas, although more abundant.
Wildlife
The most important macrofauna in the lagoons are Trichoptera, Diptera, Simulidae, Chironomidae, Ephemeroptera and amphibians (Triturus boscai, Bufo bufo and Rana temporaria), although Heteroptera are also seen, gyrinid and Acilius coleoptera, megaloptera, mites and arachnids, as well as odonates, especially in the one below (Aeschna cyanea and zygoptera), in which there are also water rats.
Peña Velosa is inhabited by molluscs (Ancylus fluviatilis and Pisidium) in addition to the invertebrate groups that also occur in the lagoons.