One of the best known and most discussed mountains in Greece is mount Grammos. It is known both for its ecological value and the role it played during the Greek civil war. It belongs to the “Natura 2000” network. To the west it borders to Albania, while to the East it reaches the Arena mountain range. It stands out for its rich flora and fauna.
On its western side it has the same borders with Albania, while on the eastern side it goes beneath the steep sides of Arenes. In autumn, the deciduous trees transform the landscape into a colorful canvas. Among the species that have been recorded on the mountain are the beech, the oak and the mountain pines (pinus nigra and pinus leucodermis).
Environmental organization “Arktouros” characterizes the area as one of the most important habitats of the brown bear (Ursus arctos), which is an endangered species in Greece and in Europe. Also one might encounter the wolf, the chamois (Rupicapra rupicapra) , the European otter (Lutra lutra) and many kinds of birds like the eagle, the hawk etc. Two great rivers Aliakmonas and Sarantaporos begin their flow in the area. The mountain's summit is called Tsouka Petsik and is located at an altitude of 2520 meters. Without snow, it is rather easy to approach.
As the days are rather short during the winter, you will have to start you journey at night so as to be able to return back during daylight. Two of the best known villages in the area are Aetomilitsa and Grammousta. From the latter it is possible to reach one of the largest alpine lakes in Greece, Gkistova. Another lake, known as Moutsalia, is located east of the “Epano Arena” peak.
Grammos is also known for the battles that took place there between the National Army and the Rebels. The 90000 soldier of the National Army had to encounter the 4500 rebels of Grammos and another 7500 in Vitsi. In cooperation with the Americans that even used napalm bombs, they managed to occupy the whole mountain range and at last the location Kamenik where the civil war ended.
There are different shelters on the mountain. In Aetomilitsa there is a hostel as well as in Grammousta.
Alpine lakes Gkistova and Moutsalia are worth seeing. The first is located at an altitude of 2.350m and is one of the greatest alpine lakes in Greece. The area is suitable for camping and not far from Tsouka Petsik peak. The second lake is situated eastern of Arenes peaks and can also be reached by car.
Two of the best known villages in the area are Aetomilitsa and Grammousta. The first was the headquarters of the communist party government during the Greek civil war.

Source: mountainsgreece.com