Ulaanbaatar is the capital and most populous city of Mongolia. It has a population of 1.6 million, and it is the coldest capital city in the world by average yearly temperature. The municipality is located in north central Mongolia at an elevation of about 1,300 metres (4,300 ft) in a valley on the Tuul River. The city was founded in 1639 as a nomadic Buddhist monastic centre, changing location 29 times, and was permanently settled at its modern location in 1778.