The monastery of Costamonite stands in the secluded thicket of the forest, in a picturesque place about half an hour’s walk from the port on the north-eastern side of the mountain, between Zohraf and Dohyar. This monastery is dedicated to the Holy First Martyr Stephen.

According to an early tradition, the founder of the monastery was the Emperor Constantine the Great. After the death of the Emperor, his son Constance completed the work which father begun. The first mention of the monastery is contained in the documents of the 11th century, but in general about its history until the XV century (when it was burned by Catalan mercenaries) little is known.

In later times, this monastery was assisted by the ruler of Serbia, George Brankovic, as well as the Serbian princess Anna. Their gifts helped Kostamonite to survive in difficult times, but like many other monasteries, he eventually failed to pay the taxes required by the Turks, and in the middle of the XVII century there were only 6 monks stayed.

The revival of the monastery began at the dawn of the nineteenth century, thanks to the efforts of the Rector of Chrysostom. According to the strange whim of history, the prior Chrysostom supplied the funds of Kira Vasiliki, a Christian, the wife of the notorius Ali Pasha, whose troops raged in Meteora. She gave to prior large sums of money during his visits to Ioannina. On her donation was restored part of the building of the monastery. She gave the monastery the Gospel in silver frame, decorated with enamel, which is still kept in the altar. In the future, the whole monastery was restored on donations from Russia.

The cathedral dedicated to St. Stephen was erected in 1869-1871. There are four other temples, behind a monastic gate and five more small temples and chapels. In the monastery there are three miraculous icons — the Virgin Mary of Portaitissa, the second icon — the image of St. Stephen, miraculously arrived at the monastery from Jerusalem during the era of iconoclastic persecution, the third icon of the Mother of God «Antiphonitria» («Giving Answer»). The monks say that one day on the feast of St. Stephen, the brother in charge of the pantry, noticed that there was almost no oil in the monastery. The Mother of God responded to his prayer and filled the oil with a large jug, standing under Her icon. This jug still shows pilgrims.

To the shrines of the monastery belong the Vain Tree, set in the silver Cross, the right hand of St. Stephen, the relics of St. Andrew, the fragment of Christ’s garment, the shoulder blade of Constantine the Great, the relics of many saints.

The library of the monastery contains ancient manuscripts of the XI and XII centuries.

In the cathedral church there are miraculous icons of the Mother of God «Odigitria» and St. Archdeacon Stefan. Icon of the Mother of God «Odigitria», was in the Vlaherna temple in Constantinople which was presented as a gift to the monastery by the Serbian princess Anna.

Today in the monastery there are about 30 monks.