Kuala Lumpur, officially the Federal Territory of Kuala Lumpur, or more commonly called KL is the national capital of Malaysia as well as its largest city. The city covers an area of 243 km2 (94 sq mi) and has an estimated population of 1.7 million as of 2015. Greater Kuala Lumpur, also known as the Klang Valley, is an urban agglomeration of 7.2 million people as of 2013. It is among the fastest growing metropolitan regions in South-East Asia, in terms of population and economy. Kuala Lumpur is the seat of the Parliament of Malaysia. The city was once home to the executive and judicial branches of the federal government, but they were moved to Putrajaya in early 1999. Some sections of the judiciary still remain in the capital city of Kuala Lumpur. The official residence of the Malaysian King, the Istana Negara, is also situated in Kuala Lumpur. Rated as an alpha world city, Kuala Lumpur is the cultural, financial and economic centre of Malaysia due to its position as the capital as well as being a key city. Kuala Lumpur is one of three Federal Territories of Malaysia, enclaved within the state of Selangor, on the central west coast of Peninsular Malaysia. Since the 1990s, the city has played host to many international sporting, political and cultural events including the 1998 Commonwealth Games and the Formula One Grand Prix. Kuala Lumpur has undergone rapid development in recent decades. It is home to the tallest twin buildings in the world, the Petronas Twin Towers, which have become an iconic symbol of Malaysia's futuristic development.