The Mesrop Mashtots Institute of Ancient Manuscripts (Armenian: Մեսրոպ Մաշտոցի անվան հին ձեռագրերի ինստիտուտ (Mesrop Mashtots'i anvan hin dzeragreri institut)), commonly referred to as the Matenadaran (Armenian: About this sound Մատենադարան), is a repository of ancient manuscripts, research institute and museum in Yerevan, Armenia. It holds one of the world's richest depositories of medieval manuscripts and books which span a broad range of subjects, including history, philosophy, medicine, literature, art history and cosmography in Armenian and many other languages.