Ten kilometers away from Pelei of Didima, at the northern slopes of mount Avgo and at a short distance from the village of Didima of Ermionida , there is the Monastery of the Holy Great Demetrius the Myrth or customary called the “Avgo Monastery” . It seems that the monastery operated in the middle ages, perhaps the 2nd half of the 15th century or the 1st half of the 16th, while sources of 1700 state that it had 16 monks and an equal number of servants.
Originally, before the establishment of the monastery, there were caves – cloisters in the area, obviously the first core of monasticism. One of them, the cave of Metamorphose, has its entrance on the roof of the monastery and maintains fragments that – according to experts – date back to the 11th to 12th century.
The monastery will take part in the Greek revolution and the monks will be on the side of Paparsenis. The Abbot of the monastery, who fought in the siege of Nafplio, was captured from the Turks and was hung in the Palamidi Castle on 10.4.1821 when the Turks came out from the Castle suddenly and took by surprise the Greek besiegers who were celebrating the Greek Easter. A year later (1825) the monastery will be burnt out by the troops of Ibrahim, while in 1834 the last monk of the monastery died. By a Royal Decree of King Otto, the monastery will be dissolved and its assets will pass to the State. A large part of them will be distributed to the landless in 1930.
Today the monastery has no monks. It operates only a few times a year by the vicar of the parish of Didima and the priests of the surrounding areas at the feast of St. Demetrius on October 26th and at the feast of St. Theodore on Saturday of the first Week of Lent.