The Holy Monastery of Philotheou stands among chestnut trees on a plateau on the north-eastern side of the peninsula, near the ancient Temple of Asclepius. It was founded by the Blessed Philotheus around the end of the 10th century.

Among the Byzantine Emperors who made donations to the Monastery are Nicephorus Botaneates in the 11th century, Andronicus II, Andronicus III, John V in the late 13th and in the 14th century. Among Serbian princes, Stefan Dushan (1346) helped to provide the manpower for the Monastery. During the early years of Turkish rule, in the early 16th century, the Abbot Dionysios, known as the Blessed Dionysios of Olympus, succeeded in turning it from an idiorrhythmic into a coenobitic monastery. However, the reaction of Bulgarian-speaking monks was such that he was forced to leave the Monastery. In about the mid 17th century, the Tsars of Russia gave permission to the monks to go there every seven years on alms missions. Grigorios Ghikas was one of the Monastery's best known benefactors.

Philotheou has six chapels and three outlying chapels. Of its 12 kellia, half are now uninhabited.

Treasures kept within the monastery

The right hand of St John Chrysostom, a piece of the True Cross, other relics of saints, vestments, and sacred vessels. The library contains 250 manuscripts, two liturgical scrolls, and about 2,500 printed books (of which some 500 are in Russian and Romanian). The Monastery is dedicated to the Annunciation of the Blessed Virgin, and since 1574 it has occupied twelfth place among the Athonite monastic foundations. Since 1973 its has followed the coenobitic system. At present it has about 60 monks.

Miracle-working icons

Our Lady Glykophilousa. It is believed that the icon was painted by Apostle Luke on the both sides. The outer side of the icon depicts Theotokos gently kissing Baby Jesus with joy and the inner side depicts Crucifixion. According to the myth, in the Age of Iconoclasm (726-842) the icon was thrown in the sea by pious Victoria, the wife of  patrician Simeon. The monks found it by the monastery’s berth where a spring is located since then.

Our Lady Gerontissa According to the myth the icon was miraculously transferred to the monastery from the city of Nigrita.