In the southern region of the peninsula of Athos, in the forests that cover the hills of the eastern coast, stands the Karakallos Monastery, an unexpected and peaceful presence in a landscape that looks virgin. The pilgrim arrives from the town of Karyes either by car or by a walk of three hours on an excellent path. The elegant tower and the compact volume of the complex on a ridge, backed by retaining walls, create the first impression of a medieval castle. The visible structures are of course more recent, most of them dating from the 16th to the 18th centuries. Yet, how old is the Monastery?