PERMITTED USE: This image may be downloaded or is otherwise provided at no charge for one-time use for coverage or promotion of National Geographic magazine dated September 2011 and exclusively in conjunction thereof.Â No copying, distribution or archiving permitted.Â Sublicensing, sale or resale is prohibited.
REQUIRED CREDIT AND CAPTION: All image uses must bear the copyright notice and be properly credited to the relevant photographer, as shown in this metadata, and must be accompanied by a caption which makes reference to NGM.Â Any uses in which the image appears without proper copyright notice, photographer credit and a caption referencing NGM are subject to paid licensing.
Photo by Randy Olson/National Geographic
Its steaming streets crammed with vendors, pedestrians, and iconic Ambassador taxis, Kolkata throbs with some 16 million peopleâand more pour in every day from small towns. In 1975 only three cities worldwide topped ten million. Today 21 such mega cities exist, most in developing countries, where urban areas absorb much of the globe’s rising population.