Mumbai is the capital city of the Indian state of Maharashtra. It is the most populous city in India, most populous metropolitan area in India, and the eighth most populous city in the world, with an estimated city population of 18.4 million and metropolitan area population of 20.7 million as of 2011. Along with the urban areas, including the cities of Navi Mumbai, Thane, Bhiwandi, Kalyan, it is one of the most populous urban regions in the world. Mumbai was officially known as Bombay. It is the most populous city in India with a large number of tourist spots. The estimated population of this city is 18.4 million. In fact, it is also one of the most populous urban regions in the world and the second most populous metropolitan area in India. It has a population of 20.7 million as per the census of 2011. It lies on the west coast of Indian with a deep natural harbor. It is considered as the wealthiest city in India.