High Quality Content by WIKIPEDIA articles! Kuala Lumpur is the capital and the second largest city in Malaysia by population. The city proper, making up an area of 243 km2 (94 sq mi), has a population of 1.4 million as of 2010.Greater Kuala Lumpur, also known as the Klang Valley, is an urban agglomeration of 7.2 million. It is the fastest growing metropolitan region in the country, in terms of population and economy.