The Holy Mountain

When it comes to national treasures, Mt Athos is right up there with the Acropolis in Athens. Halkidiki's easternmost peninsula is the world's one and only monastic republic, ruled over by the black-robed monks of its medieval monasteries. As such access to it is restricted, with all women – and female animals except cats – forbidden to set foot on its shores.All of which makes this cruise the best – and only – way to see it. Sit back and soak up the sun as your boat sails along the peninsula, giving you close-up views over the monasteries, which are literally perched on the cliffs. It's a fascinating glimpse into the monks' secret world.And you can't miss the actual Mt Athos, or Holy Mountain, rising up just over 2,000 metres from the peninsula's southern tip – it's a pretty inspiring sight. Later, your boat will arrive at Ouranopoli, where you'll have time for lunch before sailing home.