Additionally Cilegon is one of the vital assets of the state, because in this town there is a wide range of important objects such as the Merak Harbour, the Krakatau Steel Industrial Zone (including the PT.

Krakatau Steel Tbk, Asahimas, Siemens, KS - POSCO joint venture, Chandra Asri, and Pertamina), PLTU Suralaya, Power plant Krakatau, Krakatau Tirta Industrial Water Treatment Plant, the Sunda Strait Bridge Construction (Lot Plan) & Sunda Strait Industrial Zones.

Located in the most western part of Java, Cilegon's wet season rainfall peak is January with average monthly rainfall of 319 millimetres (12.6 in), and its dry season low point is August with a monthly average of 71 millimetres (2.8 in).

The high population growth rate of Cilegon is primarily caused by migrants entering the city.

A proposal to build a Batak Protestant Christian Church in Cilegon was rejected by local residents, which forces religious services to be conducted in Serang City.