An early-fourteenth-century capital of the Delhi sultanate, Tughluqabad is a prototype for the planning of many later cities. The ruins of Tughluqabad represent the extent of the architectural design and engineering skills of the time, while the street layout and other urban features remain as the earliest existing example of Indo-Muslim urban planning and its architectural components. In this report the survey of the major fortified gates with their corridors and guard rooms is presented, along with the granaries built to sustain the town in the event of siege or famine. A detailed study of the systems for controlling the water supply also shows how the flood plain was dammed and the water level managed by an ingenious system of sluices to create an artificial lake which supplied the moat and town. The report is part of the project of survey of Tughluqabad initiated in 1986 and complements the two earlier interim reports in BSOAS, 57 (1994) and 62 (1999), in which the architectural remains were studied together with urban planning and the method for construction of the town.