Kolkata, formerly known as Calcutta, is one of the world's most populous cities, with more than 13 million people inhabiting a metropolitan agglomeration that stretches outward from an urban core to envelop an expansive peri-urban hinterland, according to the Census of India in 2001. Known in popular discourse as the “black hole,” Kolkata is seen to embody the stereotypes of third world megacities: crushing poverty, filth and disease, jostling masses, slums, and underdevelopment. In this imagination, Kolkata is also rescued by saintly figures, such as Mother Teresa and her tireless work for the city's beggars, lepers, and orphans, and it is thus also the “City of Joy,” where compassion and humanity emerge from misery.