It is an old Athonite monastery that was founded in the early 10th century and was destroyed just before 1198. It is located approximately 2km east of Ouranoupoli, just outside the limits of Mount Athos, in a position known as Fragokastro (just 40m outside the borders of Mount Athos). According to data, it seems to be one of the oldest monastic institutions on the Athonite peninsula. It was discovered by a 1984 excavation that took place by archaeologists headed by Joachim Papaggelos. The 10th Ephorate of Byzantine Antiquities is responsible for the archaeological research.
According to the scientific director of the excavation "Mount Athos is constantly renewed ever since it started being populated. Thus, if someone wants to study the monasteries located inside in terms of archaeology, building and organization of the worship space has to look else ware. It was founded in the 10th century and was already deserted by 1198. It suffered very little destruction –so everything there is of the ancient Mount Athos”.
In the excavation site visitors will admire the castle, the towers and mainly the Catholicon of the monastery which is being excavated. The castle consists of five construction phases, all older than 1211. The surface inside the walls is 5,5 acres and the walls had 11 towers –some of which are being restored.
When St. Athanasios the Athonite, founder of Megistis Lavras monastery, first came to Mount Athos around 958, he settled in the region of the monastery and made the first ascetic test under the supervision of an elder monk. However, the first report of the name Zygou is made in a 942 document, in which it is not specified if this name refers to a location, a monastery or a settlement. The first accurate report about its existence was in 992, when it was already an important monastic center with a significant part in the operation of the Athonite state. In 1018, when Nephon was abbot, its properties increased with the land granted by the Athonite community. At the same time, the building complex expanded and the new Catholicon (main church) was built. During the 11th century, the monastery was one of the most important in Mount Athos, highly ranked in the hierarchy.
It seems that the building complex found by the excavations, was built in a century. It is a five-side castle, fortified by ten or eleven towers. The monastery was abandoned in the late 12th century for unknown reasons and it was granted by a Golden Bull, together with its dependencies, to the reestablished Hilandariou monastery.
In around 1206, a Frank lord who repeatedly attacked Mount Athos –event that stopped in 1211 by the intervention of the Pope of Rome- seems to have settled in the monastery. That is why the remains of the monastery were known and are often referred to –in maps also- as Fragokastro.
The abandonment and the abstraction of stones for construction material until 1980, transformed the monastery into a pile of ruins. Six limekilns operated inside and around it. It is reported that the lime needed for the construction of the building of Xenia hotel in Ouranoupoli in 1960, came from here. The 10th Ephorate of Byzantine Antiquities, which is responsible for the archaeological research, has archives containing valuable information regarding the monastery. After the last excavations, it was found that the monastery was built on foundations existed from 4th century B.C. until 6th century A.D. The building complex consists of the old core (the western), which had been doubled to the east.
The Catholicon is located in the extension that started being built in the middle 11th century. It consists of four, clearly distinct, construction phases. The complex, four-pillar, main temple with its narrow narthex was built first. Next, they built, the northern chapel with the founder’s tomb, then the outer narthex and lastly the south, one spaced, domed chapel also with a founder’s tomb. The construction of the three official tombs in contact with the south wall of the Catholicon followed. It is a cruciform temple with two burial chapels.
The murals at 2-4m height are preserved. Its marble parts, masterful pieces of art, were partly looted at a very early stage and most of the remaining were in pieces. The four pillars holding the dome are missing, but the marble diaphragm of the northern opening of the main temple is still preserved almost intact. The inside of the temple was coated with fine-grained, pressed plaster and had murals. Parts of the large presentation of the Annunciation and gem-studded crosses are preserved in the narthex. Two layers of murals with the presentation of an hierarch, probably St. Nicholas, were discovered in the niche of the southern chapel.
There are marble additions of excellent craftsmanship preserved in good condition on the floors of the Catholicon and the northern chapel, probably work of the 11th century. An oil mill complex was established in the narthex, during the 16th-17th centuries when the Catholicon was deserted. A second oil mill was established at the same time in an already deserted building located in the yard of the monastery, but their operation stopped before 1858.
The excavations brought many findings to light. The most important movable findings are the marble decoration and the marble additioned, mosaic floors, which are a feature of byzantine architecture. Furthermore, three lead seals of the 11th century, book shutters, a silver-coated medal with a carved presentation of St. Paraskevi, a tiny seal, a pectoral tablet with the presentation of an Archangel, glass pebbles from a wall embedded mosaic, bronze needles and thimbles, knives, coins of the 11th and 12th centuries, glazed pottery and glass vases of the same era stand out among the small findings.