Ulaanbaatar — Capital of Mongolia

Ulaanbaatar did not start out as a fixed city at all. It began in 1639 as a mobile Buddhist monastic center called Örgöö, built to serve as the seat of the newly recognized Bogd Gegeen, and for well over a century it moved along with its monastic community, relocating dozens of times — traditional accounts put the number at around 20 to 30 moves — before finally settling at its present site on the Tuul River in 1778.

Under Qing and later sultanate-era Mongolian administration the settlement was known internationally as Urga, and its Mongolian name for much of this period was Niislel Khüree ('capital camp'). It kept that name and its status as the religious and political capital of Outer Mongolia through the 1911 declaration of independence and the theocratic government of the Bogd Khan that followed.

The city took its current name, Ulaanbaatar ('Red Hero'), in 1924, honoring Damdin Sükhbaatar, the revolutionary commander who led Mongolian forces in the 1921 revolution that, with Soviet backing, ended Chinese control and set Mongolia on the path to becoming the world's second communist state after the Soviet Union itself.

Ulaanbaatar holds the distinction of being the coldest national capital in the world by average annual temperature, a product of its high elevation (roughly 1,300 meters) and its position deep in the continental landmass of Central Asia, far from any moderating ocean influence — winters routinely drop well below −20°C, a climate that has shaped everything from the city's traditional ger (yurt) districts, still home to a large share of residents, to its notorious winter air pollution from coal-burning heating stoves.

As the country's only large city, Ulaanbaatar now concentrates roughly half of Mongolia's entire national population within its metropolitan area, an outsized share driven by decades of rural-to-urban migration following the collapse of collectivized herding after the 1990 democratic transition, making it both the political seat and by far the dominant economic center of a country whose population outside the capital remains heavily rural and pastoral.

Gandantegchinlen Monastery, one of Mongolia's most important Buddhist religious sites, is among the relatively few monasteries to survive the Stalinist-inspired purges of the late 1930s, when the Mongolian communist government destroyed hundreds of monasteries nationwide and killed or imprisoned thousands of monks; Gandan was permitted to remain partially open, in part for propaganda purposes to demonstrate religious tolerance to foreign visitors, and it re-emerged as a fully active center of Buddhist practice after the 1990 democratic transition ended state restrictions on religion.

The city's main central square has itself been renamed more than once in recent memory: long known as Sükhbaatar Square after the 1921 revolutionary leader, it was officially renamed Chinggis Square in 2013 to honor Genghis Khan, before the government reversed the change and restored the Sükhbaatar name in 2016 — a small but telling example of how Mongolia's national symbols continue to be actively renegotiated between its revolutionary-era and much older imperial-era historical identities.

Ulaanbaatar hosts Naadam, Mongolia's most important annual festival, each July at the national stadium and surrounding grounds, featuring the 'three manly games' of wrestling, archery, and horse racing that trace back to traditions used historically to keep Mongol warriors combat-ready; the modern festival also marks the anniversary of the 1921 revolution that gave the city its current name. The Zaisan Memorial, a large Soviet-built monument on a hill overlooking the city, commemorates Soviet soldiers who died in World War II and offers one of the most popular panoramic viewpoints over Ulaanbaatar, its circular mural depicting scenes of Soviet-Mongolian friendship still intact from its 1979 construction.

The city has also struggled in recent decades with severe winter air pollution, driven largely by coal burning in the ger districts that ring the urban core, where many rural migrants without access to the centralized heating grid burn raw coal for warmth during winters that regularly fall below −20°C, making Ulaanbaatar's air quality among the worst of any capital city in the world during peak winter months.