The fortress of Tughluqabad stands on a rocky hill, 8-km
away from the Qutub Minar
Complex, on the Qutub-Badarpur Road. Built By Ghiyath-ud-Din
Tughluq, it constitutes the third city of Delhi.
Roughly octagonal on plan with a perimeter of 6.5-km, its 10 to 15m high rubble built walls are provided with bastions and gates at intervals. On its south was a vast reservoir created by erecting bunds between hills to the east. A causeway connected it with Ghiyath-ud-Din's tomb, standing amidst waters, while a wide embankment near its south eastern-corner gave access to the fortress of Adilabad, built a little later opposite on another hill.
Tughlaqabad was divided mainly into three portions. To the east of the present entrance from the Qutub-Badarpur road, a rectangular area with high walls and bastions served as the citadel. A wider area immediately to the west, similarly bounded by rubble walls and bastions, housed the palaces.
Beyond this to the north lay the city, now marked by ruins of houses. Streets in the city, some of which can be traced even now, ran in a grid-pattern from gates on one side to those on the opposite side. Inside the citadel-enclosure is a tower known as Bijai-Mandal and remains of several halls, including a long underground passage.
Near the embankment connecting it with Adilabad are sluice gates, through which water was controlled for irrigating the fields now.