Central Java city and its surrounding regencies have formed a separate special region (equivalent to a province) since Indonesian independence, administrated separately. Located in the middle of the island of Java, the Central Java province is bordered by West Java and East Java provinces. A small portion of its south region is the Yogyakarta Special Region province, fully enclosed on the landward side by the Central Java province. To the north and the south, the Central Java province faces the Java Sea and the Indian Ocean. Central Java includes offshore islands such as Karimun Jawa Islands in the north, and Nusakambangan in
Romanche Trench the French navy ship "La Romanche", commanded by captain Louis-Ferdinand Martial which on 11 October 1883 made soundings that revealed the trench. The boat was coming to France after a few months scientific mission near cape Horn, part of the first International Polar Year. The trench has a depth of , is long and has an average width of and allows for a major circulation of deep ocean basin water from the west Atlantic to the east Atlantic basins. Deep water flow through the trench is from west to east with a rate of 3.6 Sverdrups (million m³/s) of water.