Halkidiki consists of three peninsulas. Mount Athos is located on the easternmost and third peninsula of Halkidiki. This peninsula starts 2.5 km outside Ouranoupoli, from the ruins of the monastery of Zygos and ends at the foot of Mount Athos.

The peninsula of Athos is 57km long, 10.5km wide and has a total surface area of 336sq.km.