Da Nang is the fifth largest city in Vietnam after Ho Chi Minh City, Hanoi, Haiphong and Can Tho in terms of urbanization and economy. Located on the coast of the South China Sea at the mouth of the Han River, it is one of Vietnam's most important port cities. As one of the country's five direct-controlled municipalities, it is under the direct administration of the central government.

Da Nang is the commercial and educational centre of Central Vietnam, as well as being the largest city in the region. In addition to its well-sheltered, easily accessible port, Da Nang's location on the path of National Route 1A and the North–South Railway makes it a hub for transportation. It is located within 100 km (62 mi) of several UNESCO World Heritage Sites, including the Imperial City of Hue, the Old Town of Hoi An, and the My Son ruins. The city was previously known as Cửa Hàn during early Đại Việt settlement, and as Tourane (or Turon) during French colonial rule. Before 1997, the city was part of Quang Nam-Da Nang Province.

On 1 January 1997, Da Nang was separated from Quảng Nam Province to become one of four independent (centrally controlled) municipalities in Vietnam. Da Nang is listed as a first class city, and has a higher urbanization ratio than any of Vietnam's other provinces or centrally governed cities.

Sydney is the state capital of New South Wales and the most populous city in Australiaand Oceania. Located on Australia's east coast, the metropolis surrounds Port Jackson and extends about 70 km (43.5 mi) on its periphery towards the Blue Mountains to the west, Hawkesbury to the north, and Macarthur to the south. Sydney is made up of 658 suburbs, 40 local government areas and 15 contiguous regions. Residents of the city are known as "Sydneysiders". As of June 2017, Sydney's estimated metropolitan population was 5,131,326, and is home to approximately 65% of the state's population.