Mirza Ghalib may have been indulging in hyperbole when he penned these famous lines, but there is no denying that Delhi is a notch above the other great metropolises of India. What sets it apart is the multitude of historic ruins that are almost everywhere. Every ruler down the ages wished to adorn his beloved Delhi, to leave a mark that would last and so left behind a landscape studded with jewels from the past.

Neophyte New Delhi has been quick to discard most of them on the rubbish heap of history, choosing to validate a bare minimum with a name, an identity and a place of visibility.

Where it was possible to make the law look the other way, many of these monuments were razed to the ground to make way for colonisation and development. Regarded as no more than inconvenient piles of rock, many have been pulled down, built upon, built around.

Invisible City: The Hidden Monuments of Delhi explores this other Delhi-the little-known, seldom-visited, largely unheard of Delhi, the Delhi that has been rendered almost invisible.