Aya Yorgi Monastery is the monastery located in Büyükada. According to the information obtained from the Patriarchate records, the date of the construction of the Aya Yorgi Monastery is 1751. The little church, chapel and prayer place built on this date is known as the old church and it is a small two-storey building covered with tiles. The church, made of cut stone behind the bell tower on the hill, is the new Aya Yorgi Church and was built in 1905 and opened for use in 1909.
St. George Koudonas Monastery is located in Yüce Tepe, which is located in the southernmost of the two hills on the island. There is a road that reaches this monastery from the square in the middle of the island.
According to rumor, the monastery II. It was founded in 963 during the reign of Nicephorus (9-963). This monastery is mentioned for the first time in history in the list prepared by I. Manuel Comnenus in 1158. The name Koudonas, which means “bells” in Greek, comes from the following story: When a shepherd grazes a day herd on this hill, he hears bells coming from the depths of the ground. When he digs the ground to see what happened, he later finds a picture of St. George, placed by himself and other locals in the place where the monastery was founded. This story goes back to 1625 and probably tells of the times when the monastery was rebuilt rather than first built. Legend aside, Isaias, the first registered encyclopedia of the monastery, began the construction of the current katholikon in 1752 and completed the main church of Blachernitissa seven years later, and also added many small rooms belonging to the monastery. In the half century that followed, several additions were made by the priests Anthemios and Arsenios. Meanwhile, some miracles have been attributed to the painting of St. George, in particular, to improve mental illnesses and to save the "captured by sinful spirits" from the influence of these spirits.
The current facility consists of six separate churches and places of worship on three floors - older temples on lower floors. On the ground floor there is the house of the priest and the main church of St. George. Both structures were built in the early 20th century. On the southern inner wall of the church, there is an original icon of Hagios Georgios Koudonas, which is covered with silver today.
The room at the bottom of the stairs is a blessed room with a holy spring. This room, according to rumors, is the place where St. George's sacred image was dug up. Beyond this room is another temple dedicated to the Apostles.
Celebrated on the 23rd of April, St. George's Day, thousands of pilgrims from all over the world - including Muslim Turks and people from other religions - set out on the road to the monastery. Many go barefoot to attend the dawn ritual. After the rite, many of the pilgrims have lunch at the open restaurant at the peak of the hill, celebrating the traditionally heralding the arrival of spring according to the old calendar. The restaurant serves simple meals and appetizers alongside its own unlabeled red wine. The peak of the hill is surrounded by pine, cypress and many more trees, and an atmosphere resembling the Greek islands, especially when the monastery's bells ring in this ancient temple. The view, which is visible from the peak of Yüce Tepe and includes all the islands and the Asian shores of the Marmara Sea, is magnificent.