Located on the northwest coast of Java, Jakarta is the country's economic, cultural and political centre, and with a population of 9,761,407 as of December 2012, it is the most populous city in Indonesia and in Southeast Asia.akarta is located on the northwest coast of Java, at the mouth of the Ciliwung River on Jakarta Bay, which is an inlet of the Java Sea. Officially, the area of the Jakarta Special District is 662 km 2 (256 sq mi) of land area and 6,977 km 2 (2,694 sq mi) of sea area.