Choibalsan

The location has been a post on a trading route for centuries. In the 19th century it grew into a city, and became the economic hub of eastern Mongolia in the twentieth century and is still serving as an active economic center for Eastern Mongolia. Due to the city's proximity to the site of the Battle of Khalkhin Gol, it contains a museum dedicated to Georgy Zhukov, hero of the battle.

Choibalsan experiences a cold semi-arid climate (Köppen BSk) with frigid, very dry winters and warm, wetter summers. In terms of temperatures it resembles a humid continental climate (Dwb), but falls short of that classification due to the very dry winters. Extreme temperatures range from a minimum of −41.1 °C (−42.0 °F) on 1 January 1959 to a maximum of 41.9 °C (107.4 °F) , recorded on 3 August 2016.

The Choibalsan Airport (COQ/ZMCD) has one paved runway, and is served by regular flights to Ulaanbaatar, and Hailar and Manzhouli in Inner Mongolia, China. There is a railway line (unconnected to the rest of the Mongolian rail network) that connects Choibalsan to the Trans-Siberian Railway (the original routing) in Borzya, Russia; although there are no passenger service across the border: passenger trains from Choibalsan terminate in Chuluunkhoroot (Ereentsav).

The city of Choibalsan has a population of 45,490 (1994), 41,714 (2000), 36,142 (2003), 39,500 (2006), 39,500 (2007, 53.2% of the Dornod Aimag's total population), 38,150 (2008, 51.2% of the Aimag's population) and 38,537 (2025). Choibalsan is inhabited primarily by Halh Mongols, with smaller numbers of Buryats, Barga Mongols, and Üzemchin.