Ho Chi Minh City, abbreviated as HCMC, also known by its former name Saigon, is the most populous city in Vietnam with a population of 9 million (13 million in the metropolitan area) as of 2019. Located in southeastern Vietnam, the metropolis surrounds the Saigon River and covers about 2061 km2. From 1955 to 1975, Saigon was the capital of the Republic of Vietnam, commonly known as South Vietnam.