Ertij is a fort built during the 13th century. It is situated upon a hill adjacent to the village of Arpi in the Vayots Dzor Province of Armenia. Nearby in the gorge carved by the Arpa River is the cave shrine of Jrovank.

• Kiesling, Brady (2005), Rediscovering Armenia: Guide, Yerevan, Armenia: Matit Graphic Design Studio
• Kiesling, Brady (June 2000). Rediscovering Armenia: An Archaeological/Touristic Gazetteer and Map Set for the Historical Monuments of Armenia (PDF). Archived (PDF) from the original on 6 November 2021.

• Armeniapedia: Areni Church & Ertij Fort