India, Nov. 2 -- A walk through north Kolkata is a lesson in anachronism. Its narrow, mazy lanes are flanked by cramped residential blocks and sprawling ancestral mansions in equal measure. Its neighbourhoods struggle to breathe and offer vast open spaces in the same breath.

Historically home to prominent families such as the Tagores, Mullicks, Chatterjees and Seals, north Kolkata is where Durga Puja took on its modern, community-driven shape centuries ago. The neighbourhood's pujas now draw hundreds of thousands of people every year, packing them into streets planned and built for far more modest numbers.

On the evening of October 17, Saptami, families dressed traditionally for Durga Puja filled those lanes. Thousands filed through a n...