The district of Kolkata is the main administrative district of the state of Bengal. The district has the city of Kolkata as its main centre for the administration of the district as well as the state of Bengal. The city of Kolkata is also the capital city of the state apart from being administrative centre for the district of Kolkata. The district of Kolkata is literally a complete metropolitan district with literally no rural population. The great River Ganges flows through the heartland of the district making the district a great location for trade and commerce. The city of Kolkata was the capital of India under the British Rule. The district has an area of approximately 185 sq km with a population of around 50 lacs. The density of population of the district is approximately about 25000 individuals per sq km making Kolkata one of the most crowded regions all over the world.