-What you can expect- Towering 2,000m above sea level, the steep slopes of Mount Athos make for a boat trip destination with a difference. Halkidiki's easternmost peninsula is the world's only monastic republic, ruled over by the black-robed monks of its medieval monasteries. Access to it is restricted, with all women forbidden to set foot on its shores, which makes this cruise the best – and only – way to see it.