It is located among the municipalities of A Estrada, Forcarei and Silleda, at a height of around 700 metres above sea level. It forms part of Brañas de Xestoso, a protected area within the Natura Network.
In relation to vegetation, Lagoa Sacra is an extensive area of scrubland and humid meadows with interesting wetlands. The existing fauna consists of a variety of amphibians and reptiles. You can also find hawks, falcons, white eagles and corn buntings, as well as mammals such as foxes and wolves.
There are legends that refer to a battle against the Moors, in which a lot of dead bodies were placed in the lagoon, which was thereafter enclosed with a wall so that it would not be profaned. This is a seasonal lagoon that dries up in the summer.