Kolkata is situated on the bank of Hooghly River, It is the main city (capital) of the Best Bengal. Kolkata also known as Calcutta, it is main educational, commercial centre of the East India. As of 2011, its population is 4.5 million, making Kolkata the third populous metropolitan area in India.
Metro: Kolkata first underground Metro railway in the India, It extends from Dumdum near Subhas Chandra Bose Air Port, Kolkata to Kavi Subhash station near Patuli, the active North-South axis of Kolkata over a length of 25.135 kms.
There is no absolutely denying of the information that Kolkata is one of the most important cities that have left through a lot of evolutions and extinctions.