Kochi ([koˈtʃːi ]), also known as Cochin (KO-chin), is a major port city on the south west coast of India by the Arabian Sea and is part of the district of Ernakulam in the state of Kerala. It is often called Ernakulam, which refers to the mainland part of the city. Kochi is the second largest city on the western coast of India (after Mumbai), with a total metropolitan population of 2.1 million. It is the second largest city corporation in Kerala with a corporation limit population of 612,343 and is part of an extended metropolitan region, which is the largest urban agglomeration in the state. Kochi city is also a part of the Greater Cochin region and is classified as a Tier-II city by the Government of India.