Halfway between Monte San Biagio and Fondi, inside the Regional Park of Ausoni, rises Mount Arcano: at its feet the Monastery of San Magno, on its summit the Sanctuary of the Madonna della Rocca, which delimit the Campo Demetriano of the ancient Romans, the Valley of the Martyrs of the Christians. It was in fact in the second half of the third century that these places were the scene of an episode of the fiercest persecution of the emperors of Rome, that of Decius. An extraordinary number of Christians, including St. Magnus and St. Paternus, who took refuge in the ravines of the mountain to escape the execution of the edict, discovered, testified to their faith by sacrificing their lives. The remains of the martyrs were kept for centuries in the Roman building that stood on the source of the river Licola.\The place of martyrdom was soon an object of veneration and many followers of the new religion withdrew there in solitude, favored by the environmental conditions of this happy district.\Until Onorato, as Pope Gregorio Magno testifies in his Dialogues, in the first decades of the 6th century established in that place a real community dedicated to prayer and work. Later the Monastery of San Magno, following the Benedictine rule, will depend on Montecassino. The Monastery of San Magno knows a subsequent period of rebirth with the enlargement made by the princes of Fondi in the last decades of 1400 and its passage to the Benedictines of Monte Oliveto that led it to a new prosperity, until the suppression and the division of goods in 1807.\Only in the last years the monastic complex of San Magno, acquired and restored by the Lazio Region and finally entrusted to the archdiocese of Gaeta, has been returned to its original vocation: port of land where every traveler can give an answer to the questions of life and faith of all men and women of good will.\At the same time, the works undertaken have reserved important discoveries, among which the discovery of the medieval church with a monastery of St. Magnus with frescoes on the life of St. Benedict dating back to the eleventh century.\ The visit of the Monastery of St. Magnus that starts from the Roman building, shrine of the martyrdom of St. Magnus, built at the level of the spring that glimpses at his feet, leads us to the enchantment of the Renaissance church through the medieval one. A fascinating journey rich in testimonies that leads us back from the roots of our faith to the medieval enthusiasm and naivety, to make us land to the harmonious and responsible proposal of modernity. The summit of Monte Arcano, which can be reached by taking an easy road, reserves us the discovery of the ancient Sanctuary of San Magno.\The tradition says that the Marian cult, brought to the Demetrian camp by San Paterno, has seen the rise on the mountain a small aedicule with a fresco dedicated to Mary. This fresco depicts Mary while breastfeeding the baby Jesus, for which reason it is called Madonna del Latte (Virgin of the Milk). Perhaps this aedicule is referred to by the Latin hexameter, carved on stone and dating back to the early centuries and recently discovered, which indicates: "Here shines the dwelling of the Virgin and Mother Mary". \(lazionascosto.it)