Darkhan is the capital of Darkhan-Uul Province in northern Mongolia, and the third-largest city in the country. On October 17, 1961, the city of …Darkhan is the capital of Darkhan-Uul Province in northern Mongolia, and the third-largest city in the country. On October 17, 1961, the city of Darkhan was built with extensive economic assistance from the Comecon. As its name implies, the city was originally conceived to be a manufacturing site for Mongolia's northern territory. Polish specialists built a woodworking plant, brickworks and a lime factory in Darkhan. Hungarians built a meat factory, opened in 1974.