Dornod aymag (Дорнод аймаг) is one of the 21 provinces of Mongolia. It is located in the east of Mongolia. Its capital is Choybalsan. Choybalsan (Чойбалсан) is the fourth-largest city in Mongolia, which was named after a communist leader. ... Square kilometre (US spelling: Square kilometer), symbol km², is an SI unit of surface area. ... This article is about the year 2000. ... Image File history File links Drawn by Nanshu. ... Mongolia is divided into 21 aymags or provinces. ... Mongolia is divided into 21 aymags (provinces). ... Choybalsan (Чойбалсан) is the fourth-largest city in Mongolia, which was named after a communist leader. ...