In the mid-7th century, Muslim Arabs invaded Armenia from the east, destroying Christian religious centers and burning manuscripts. Beginning in the 12th century, waves of Seljuk Turks flooded into Anatolia, absorbing medieval Armenia. Under this new invader, religious oppression over Christians and their monuments continued.
Stone proved to preserve history and scripture better than fragile parchment. Thus, monks began inscribing information and descriptions into the walls and over doorways. They contain information about architects, sculptors, events in history, and other information pertinent to the monasteries and the lands surrounding them. These inscriptions are written in old Armenian; nevertheless, the script is identical to the Armenian script used in modern times
Hidden rooms provided a second method of historical preservation. Monks sealed manuscripts into these rooms. Other times, they would create hollow pillars filled with written work that survived not only the Arabs and Seljuks, but the Ottoman Turks, who ruled them into the 20th century. Some were so well-hidden that 19th century scholars were the first to see them since they were sealed away. The 10th-11th century complex Haghartsin (pictured below) provides an excellent example.
Another interesting feature of Hagharstin is its architectural ingenuity. Armenians, living in an earthquake ridden nation, developed layered walls to limit destruction and make repairs easier. The outer and inner walls are relatively thin slabs of stone. The interiors were a mixture of stones, eggs, garlic, and other adhesives. This provided buoyancy and absorbed shock from earthquakes. Stones slabs that did fall were easily replaced as the filling maintained integrity.
All information was given by the links provided and the Hyur Tour Agency and its incredibly knowledgeable staff.