The city of Surabaya, capital of East Java Province, is the second-largest city of Indonesia following Jakarta, the national capital. Surabaya is located at the mouth of the River Mas facing the Madura Island. Surabaya has an annual population growth rate of 0.65 per cent and a population of approximately 3.09 million people in 2018. The city has a population density of 8,458 person per km2 and is highly urbanized. The city’s borders encapsulate an area of 350 km2, divided into 31 districts (kecamatan) and 154 sub-districts (kelurahan).

Bandung is the capital of West Java Province and is the fourth-largest city in Indonesia after Jakarta, Surabaya and Medan with 2.5 million inhabitants. Its metropolitan area, Greater Bandung (Bandung Raya), or is also known in different name as Bandung Basin (Cekungan Bandung), consist of the Municipalities of Bandung and Cimahi and three regencies (Bandung, West Bandung and Sumedang). This metropolitan area  is the third-largest metropolitan area in the country with a population of more than 8.5 million inhabitants.