Tanahat Monastery is located in Vayots Dzor province, about 7 km southeast of the village of Vernashen, on the left bank of the Tanahat river, one of the tributaries of the Yeghegis river. In medieval sources the monastery is mentioned under various names — Tanahat, Tanat, Gladzor, and Gharavank.
An important source on the history of Tanahat Monastery is Stepanos Orbelian's "History of Syunik." He mentions Tanahat Monastery as a notable monastic center and links it to 8th-century events connected with the martyrdom of Stepanos Syunetsi and his grave. However, modern scholarship notes that Orbelian's historical information concerns two different places both called Tanahat, and identifying them has long been a subject of debate.
The complex consists of two main churches — the main Surb Stepanos Nakhavka (Protomartyr) church and the smaller Surb Astvatsatsin church — as well as the remains of a gavit (narthex), a cemetery, and other structures. The surviving main structures are dated to the 13th century.
In 1273–1279, on the initiative of the Proshyan princely house, the main cathedral — the Surb Stepanos church — was rebuilt on the foundations of an earlier chapel of the same name on the site; it is built of local dark basalt.
