The national path O2 is a mountaineering route of Thessaly that crosses the mountains to the east.
The beginning of the path is on Olympus and in the direction of South-Southeast, after climbing first on the slopes and the ridges of Kato Olympus, Ossa (Kissavos) and Montenegro it reaches up to the mountainous volume of Pelion.
The National path O2 starts from the base of the peak Scolio of Olympus. From this point passes the International (European) path E4 that goes up from Litochoro. The specific intersection of the two paths is also the beginning of the national path.