Colombo is the largest city and former administrative capital of Sri Lanka. It is located on the west coast of the island and adjacent to Sri Jayawardenepura Kotte, the present administrative capital of Sri Lanka. Colombo is a busy and vibrant city with a mixture of modern life and colonial buildings and ruins and a city population of 647,100 at the 2001 Census. The Colombo Metropolitan Region, defined by the districts of Colombo, Gampaha and Kalutara, has an estimated population of 5,648,000 as of 2006, and is covering an area of 3,694.20 km2.