Whilst Calcutta does have some interesting spots of architecture from the times when it was the capital of the British Raj, there isn’t much else worth really seeing in Calcutta. I would give it a miss.
If you want a big Indian city, I would suggest Mumbai and see Mumbai’s stark contrasts for tips.
Or the real highlights of India which are to be found in the Golden Triangle and Rajasthan. See the India’s Golden Triangle – getting the most out of it entry for what to prioritise.
