Ho Chi Minh City is the largest city in Vietnam with a population of 8.4 million. It is located in the south of Vietnam and is at the core centre of Ho Chi Minh City Metropolitan Area, which has a population that exceeds 20 million, 16 million of whom live in urban areas. The city is currently undergoing a period of strong economic and population growth; as it is the economic and financial hub of Vietnam, it continues to attract migrants from other provinces.

Johannesburg is the capital of Gauteng, which is the South African province with the biggest population comprising approximately the 24 percent of the overall population. As of 2016 Johannesburg had an estimated population of 4.4 million, and according to the census, the city has grown at an extremely high rate: an average of 4.1 percent between 1996 and 2001 and by 3.2 percent between 2001 and 2011. Although this urbanisation boom is projected to slow down, Johannesburg is expected to reach 7 million inhabitants by 2040.

Durban is located on the east coast of KwaZulu-Natal (KZN) Province in South Africa and eThekwini Municipality is the local government responsible for management and service provision across the eThekwini Municipal Area. Durban is the third most populous city in South Africa and the largest city in the South African province of KwaZulu-Natal. Durban forms part of the eThekwini Metropolitan Municipality and has a population of about 3.9 million.

Lagos is the largest urban agglomeration in Nigeria and one of the biggest and fastest growing megacities in the world, with population estimates ranging from 12 to over 20 million people. The built-up area is situated along the banks of the western portion of Lake Lagoon and expands to the north, following the expressway to Abeokuta and Ibadan. Although the urban extension is mainly contained within the administrative boundaries of Lagos State, the city has begun to stretch beyond its borders, expanding in the direction of the main transport routes into Ogun State.