In the autumn, in contrast, the presence of the
perennial oaks is revealed, surrounded by
deciduous species. This is one of the star
moments of the mature forest that surrounds
the high basin of the river Navia and some of
its tributaries, between Doncos and Becerreá.
The beauty of the place is apparent, even to
the travellers that drive rapidly along the
highway that crosses this natural space.
In Agüeira we cross an excellent chestnut
grove, which tends to become part of a mixed
forest of oak trees on high ground. Near Cruzul,
close to Becerreá, we will find the strange sight
of a Mediterranean holm-oak wood here in this
Atlantic domain, in a mountain area. Its presence is associated with a limestone substrata in some specific
areas of the valley.
On some stretches the hill walking routes follow the layout of the old paths, also of historical significance.
This is the case, for example, of the bridge over the river Cruzul, scene of battles which occurred two
hundred years ago, in the War of Independence.