Hachasu a village in the Gazakh uezd of the former Yelizavetpol (Ganja) governorate, later in the former Karvansara (Ijevan) district, and currently in the Tavush province. The provincial centre is located 14 km to the north of the town of Karvansara, at a height of 750 m above sea level.

The toponym was coined by combining the word “hacha” meaning “a place of separation” and the Turkic word “su” meaning “a river”. The village is called “Hachasu”, as the main river is divided into several branches.

The village was originally inhabited by Azerbaijanis who gradually left it following the settlement of Armenians in the region.

The name of the village was literally translated into Armenian in 1920 and became “Achajur”. According to the law “On the administrative-territorial division of the Republic of Armenia” dated 7 November 1995, it was integrated into the administrative area of the Tavush province.

Geographical coordinates: latitude: 40°59’ N., longitude: 45°08’ E.