In traditional local folklore the forests of the Galician System are said to be inhabited by a variety of elves, fairies, ghosts, the Santa Compaña, the Nubeiro and witches (meigas).

Geomorphologically the Galician Massif is a northwestern prolongation of the Meseta Central, the inner Iberian plateau and has great affinity with the geology of the Tras os Montes Portuguese region, so that it is considered as a whole under the name 'Galicia-Trás-os-Montes Zone'.

[1] It is composed of Paleozoic materials (granite) with metamorphic rocks such as gneiss, slate and schist in the center and west, which were subject to Alpine folding.

[2] The relief of the system, with an average height of 500 metres (1,600 ft), is relatively smooth compared with other Iberian ranges.

Generally the system includes mountains that are rounded in shape, often topped by small rocky outcrops, as well as horsts, basins and faults, roughly aligned in a N-S direction.