India, Dec. 8 -- In the mid-seventeenth century, when Mughal emperor Shah Jahan shifted his capital from Agra to the banks of the Yamuna, he imagined a city secure enough to guard an empire and grand enough to project its splendour. Thus, Shahjahanabad, the so-called seventh historic city of Delhi, was born enclosed within a formidable 13-metre-high, six-kilometre stone-and-rubble wall. With 13 monumental gateways and 14 smaller wicket gates punctuated this fortification, sealing the city's boundary between what chroniclers often described as "civilisation and wilderness," order and the chaotic world outside. The wall, originally made of mud, was rebuilt through 1657 in red sandstone. But centuries later, what survives is scattered, stresse...