A colleague and I happened upon a guard in a good mood on a day the museum was offically closed and he let us have a walk around the hallways. The treasured documents were not accessible but it was cool to get a look aroud the place...
"The Mesrop Mashtots Institute of Ancient Manuscripts (commonly referred to as the Matenadaran, is an ancient manuscript repository located in Yerevan, Armenia. It holds one of the world's richest depositories of medieval manuscripts and books which span a broad range subjects, including history, philosophy, medicine, literature, art history and cosmography in Armenian and many other languages." [ http://en.wikipedia.org/wiki/Matenadaran]