Jakarta, officially known as the Special Capital Region of Jakarta (Indonesian: Daerah Khusus Ibu Kota Jakarta), is the capital and largest city of Indonesia, and the second most populous urban agglomeration in the world. 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. The official metropolitan area, known as Jabodetabek (a name formed by combining the initial syllables of Jakarta, Bogor, Depok, Tangerang and Bekasi), is the second largest in the world, yet the metropolis's suburbs still continue beyond it. The metropolitan has an area of 4,383.53 square kilometres (1,692.49 sq mi) and population of well over 23 million.
Jakarta is listed as a global city in the 2008 Globalization and World Cities Study Group and Network (GaWC) research. Based on survey by Brooking Institute, in 2011 growth of economic of Jakarta ranked 17th among the world's 200 largest cities, a jump from its 2007 ranking of 171. Jakarta has grown more rapidly than Kuala Lumpur, Guangzhou and Bangkok.
Established in the fourth century, the city became an important trading port for the Kingdom of Sunda. It was the de facto capital of the Dutch East Indies (known as Batavia at that time) and has continued as the capital of Indonesia since the country's independence was declared in 1945. The city is currently the seat of the ASEAN Secretariat as well as important financial institutions such as the Bank of Indonesia, the Indonesia Stock Exchange, and the corporate headquarters of numerous Indonesian companies and multinational corporations. Jakarta's business opportunities, as well as its potential to offer a higher standard of living, attract migrants from all over Indonesia, making the city a melting pot of many communities and cultures.
Jakarta is served by the Soekarno–Hatta International Airport, Halim Perdanakusuma International Airport, and Tanjung Priok Harbour; it is connected by several intercity and commuter railways, and served by several bus lines running on reserved busways.
Jakarta 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 km2 (256 sq mi) of land area and 6,977 km2 (2,694 sq mi) of sea area. The Thousand Islands, which are administratively a part of Jakarta, are located in Jakarta Bay, north of the city.
Jakarta lies in a low, flat basin, ranged from −2 to 50 metres (−7 to 164 ft) with average elevation 8 metres (26 ft) above sea level; 40% of Jakarta, particularly the northern areas, is below sea level, while the southern parts are comparatively hilly. Rivers flow from the Puncak highlands to the south of the city, across the city northwards towards the Java Sea; the most important[clarification needed] is the Ciliwung River, which divides the city into the western and eastern principalities. Other rivers include the Pesanggrahan, and Sunter.
All these rivers, combined with the wet season rains and insufficient drainage due to clogging, make Jakarta prone to flooding. Moreover, Jakarta is sinking about 5 to 10 centimetres each year, even up to 20 centimetres in the northern coastal areas. To help cope with the threat from the sea, the Netherlands will give $4 million for a feasibility study to build a dike around Jakarta Bay. The ring dike will be equipped with a pumping system and retention areas to defend against seawater. Additionally, the dike will function as a toll road. The project will be built by 2025. In January 2014, Central Government agreed to build 2 dams in Ciawi, Bogor and a 1.2 kilometres tunnel from Ciliwung River to Cisadane River to ease Jakarta floods. Construction costs will be paid by Central Government, but land acquisitions is responsibility of Jakarta Authority. Nowadays, an 1.27 kilometre with capacity 60 cubic meters per second underground water tunnel between Ciliwung River and East Flood Canal is being worked to ease Ciliwung River overflows.
Jakarta has a tropical monsoon climate (Am) according to the Köppen climate classification system. Despite being located relatively close to the equator, the city has distinct wet and dry seasons. The wet season in Jakarta covers the majority of the year, running from October through May. The remaining four months (June through September) constitute the city's dry season (each of these 4 months has an average monthly rainfall of less than 100 millimetres (3.9 in)). Located in the western part of Java, Jakarta's wet season rainfall peak is January and February with average monthly rainfall of 299.7 millimetres (11.80 in), and its dry season low point is August with a monthly average of 43.2 mm (1.70 in).