Cilegon is a major coastal industrial city in Banten province, Indonesia, covering 162.51 km². It is located on the island of Java. The city had …Cilegon is a major coastal industrial city in Banten province, Indonesia, covering 162.51 km². It is located on the island of Java. The city had a population of 374,464 at the 2010 Census and 434,896 at the 2020 Census; the official estimate as at mid 2023 was 470,378.