Ertij fortress is located in Vayots Dzor province, near the former settlement site of Ertij, about 2 km southeast of the village of Arpi, in the basin of the middle course of the Arpa river. It is dated to the 12th–14th centuries as a medieval Armenian defensive structure.
Among the fortress's surviving parts are the foundations of the wall, the remains of a reservoir, traces of residential structures, and broken khachkars. In topographic records from the late 19th and early 20th centuries it was also mentioned under the name "Shirali Khan's Fortress."
