The significance of cultural heritage as an intrinsic element of the urban landscape, its tremendous socio-economic and anthropological value, and its role as an enabler of sustainable development are well recognized in the global policy discourse. Thus, heritage has been included in the United Nations’ Sustainable Development Goals 11, whose target 11.4 aims to ‘strengthen efforts to protect and safeguard the world’s cultural and natural heritage’. Despite this world-wide recognition of cultural heritage’s importance in enriching our lives, our heritage—particularly built heritage—is under constant threat because of natural and anthropogenic factors. The International Council on Monuments and Sites (ICOMOS) has identified eight different threats, of which urbanization is seen as perhaps the most significant. It manifests itself through rapid demographic changes; demolition of heritage sites; loss of identity and homogenization amongst several other processes. Delhi, the capital of India, in its recorded history of more than a millennium, has witnessed the rise and fall of several kingdoms and empires. Its story is one of innovation and sustainability, evidenced in the hundreds of buildings and structures of the past that dot the 1,453 sq. kms. that it covers today. One of the several cities that came up in Delhi is Shahjahanabad, established by Shah Jahan—the fifth Mughal emperor—in 1648 CE. Founded when the Mughal Empire reached its zenith, Shahjahanabad not only was the capital of the Empire, but also a cultural centre where arts and crafts, architecture, poetry and music flourished. Shahjahanabad today is in a state of decay and dilapidation physically, socially and economically. The pressures of development have led to a loss of valuable resources, architectural typologies and civic amenities that once contributed to the historic values of the area. Geographic information science has long been used to support preservation of cultural heritage through documentation, modelling and information dissemination. As part of an ongoing research that seeks to create a historical geographical information system for Shahjahanabad, this article uses a detailed map of the city from the 1840s to analyze the city morphology and its various features prior to its large-scale destruction in 1857. The map was geo-referenced in QGIS—an open-source GIS software—using Ground Control Points (GCPs) derived from Google satellite images. Its features were digitized to get a clearer understanding of the original layout and the changes that have taken place since 1857. Furthermore, Khas Mahal—one of the major buildings of the Red Fort that survived the destruction of 1857 was documented photogrammetrically to assess its physical condition for architectural conservation. This article thus demonstrates the immense significance and potential of GIS and photogrammetry—two facets of geo-information technology—in understanding our past and taking informed steps for its preservation.