This paper pilots an approach to identifying, categorizing, and mapping public land owned by the central, state, and local government in urban developed areas of Ahmedabad, Gujarat, India. The methodology uses information on plot sizes, location, and ownership that is publicly available for all areas covered by town planning schemes. The study examines the extent of unutilized and underutilized public land, which excludes all cemeteries, parks and gardens, heritage buildings, slums, utilities, infrastructure land, and industrial estates. Unused land already earmarked for public purposes were also excluded from the valuation exercise. The potentially marketable land so identified was valued at both official rates and estimated market rates. The value of potentially marketable excess land is significant -- in per capita terms, the high-value scenario substantially exceeds the estimate of total infrastructure investment needs for the next 20 years prepared by an expert committee of the Ministry of Urban Development of the Government of India.