In the western side of Picones de Sopeña, looking at Miera river and with an altitude of more than 800 metres, is located one of the biggest beech forests in the region: Zamina. The access difficulties of the limestone ground have had the advantage of limiting farming usage.
Beech was the last hardwood to grow on the Cantabrian mountains. Coming from the Balkans, it reached the region almost 4,000 years ago and has adapted to almost any type of ground, mainly oriented north or northeast, in high areas with abundant rains.