Kolkata is the heart and soul of India's post-Mogul culture. Tagore and Satyajit Ray are from here. This is where Indian drama, poetry and novels are gestated. It boasts an embarrassment of world-class universities, medical schools and specialist colleges. Just walk down College Street and see the biggest open-air bookshop in the world. Whatever you want, from a tome of obscure jurisprudence to the plays of JM Barrie, they're here. And up a flight of stairs next to a bookshop is the coffee house once called the Albert Hall.
It is the Brasserie Lipp, the Spago of Kolkata: a beautifully run-down room where turbaned waiters serve coffee and mutton curry on tables rubbed smooth by millions of elbows. This is where Bengalis come to argue. There is a table of theatricals; here, newspaper editors; and over there, a gaggle of girls gossiping. The thing that Bengalis do better and more than anything else is argue. They are the past masters, born with opinions and rhetorical flourishes.
Kolkata was invented by the English on the banks of the Hooghly, the last stretch of the Ganges. And it became, for most of imperial history, the capital of an India that ran from Burma to Ceylon. I initially came to look at the crumbling architecture, that glorious propagandist style, part-Mogul, part-Roman, with a touch of Home Counties vicarage. It's impressive, and a guided walk around the old capital, its churches and graveyards with their sad inscriptions putting a brave face on the vicissitudes of rebellious natives, turgid bugs, rotting alcohol and broken spirits, is all fine, but if you come from a post-colonial country, this will all be familiar stuff, though not on this scale.
What you should do is sit on a gadh, a landing stage on the river, and watch the astonishing life. Or go to the flower market and watch them make garlands. You might go to the Kalighat temple and see the most striking votive statue of Kolkata's patron goddess. You should eat Bengali fish with mustard in banana leaves, and Kolkata's famous puddings and sweets. You should play cricket on the maidan in any one of the deathly serious games. And you should start an argument with a local.
This is an edited extract from AA Gill's Here & There: Collected Travel Writing (£12.99, Hardie Grant Books), published on 17 November. British Airways flies to Kolkata. Visit ba.com.