Denver, officially the City and County of Denver, is the capital and the most populous municipality of the U.S state of Colorado. Denver is in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains. The Denver downtown district is immediately east of the confluence of Cherry Creek with the South Platte River , approximately 12 mi (19 km) east of the foothills of the Rocky Mountains. Denver is nicknamed the Mile High City because its official elevation is exactly one mile (5280 feet or 1609.3 meters) above sea level, making it the highest major city in the United States. The 105th meridian west of Greenwich the longitudinal reference for the Mountain Time Zone, passes directly through Denver Union Station.
With an estimated population of 693,060 in 2016, Denver is the 19th-most populous U.S. city, and with a 15.48% increase since the 2010 United States Census, it has been one of the fastest-growing major cities in the United States. Denver is the most populous city within a 500-mile (800 km) radius and the second-most populous city in the Mountain West after Phoenix, Arizona. In 2016, Denver was named the best place to live in the United States.