<P> Three main gates on the north, south and west are part of the fortifications of the Purana Qila, the sixth city of Delhi, built by Sher Shah Suri (1538--45). Sher Shah Suri raised his citadel after demolishing Dinpanah, the city built by Humayun . The fortifications of the Qila extended to a boundary of (2 km (1.2 mi)) on an irregularly oblong plan . Bastions adorned the corners and the western wall . Of the existing three gates, the west gate forms the entrance to the Qila and is called the Bara Darwaza (big gate). All three gates are double--storied structures built with red sandstone and have chhatris . The enclosure wall inside has cells in two--bay depth . The northern gate, built in 1543--44, is called the Talaqi - Darwaza for reasons unknown . On this gate, in the front, carved marble leogryphs in combat with a man are seen above the oriel windows . Built in random rubble masonry with dressed stone facing, the gate has a tall arch enclosed by two smaller arched openings . Two bastions adorn the gate with high ceiling rooms . On the second floor of the gate, there are two openings . Exterior surface of the gate had coloured tiles and the inner rooms were covered with incised plaster work . The Purana Qila was stated to have been left unfinished by Suri, which was later completed by Humayun . The southern gate is called the Humayun Darwaza; the reasons attributed for the name are that either Humayun built it or the gate overlooked Humayun's tomb . An inscription in ink on the gate refers to Sher Shah with the date as 950 A.H. (1543--44). </P> <P> Sher Shah gate located to the south of Khairu'l - Manazil - Masjid is said to be an entrance to the large city of Delhi that Sher Shah built in front of his fortress of Purana Qila . The gate, mostly built with red sandstone but with use of local grey quartzite in its upper storey, is thus called the Lal Darwaza (red gate). Arcades were built from this gate into the city, which were provided with series of dwellings with frontage of a verandah, which may have been used for commercial establishments . Kabuli or Khuni--Darwaza (explained in the following section) is another gate on the fringes of Sher Shah's city . ASI has undertaken extensive conservation works of the gate and its surroundings at a cost of Rs7. 5 million (US $150,000). </P> <P> Shahjahanabad, the seventh city of Delhi, was built by Shah Jahan in 1649 like a fortress encircled by strong and high red--brick walls with 14 entry gates to the city, in addition to 16 wicket gates called windows (khirkis in Urdu language). A number of bastions built of stone were added by the British, in addition to repairing the earlier fort, to make the fort more secure . The gates were designed and built for the people to have access and the royal procession to enter or exit, when going out in diverse directions . Out of the 14 gates, five gates have survived, namely, the Kashmiri Gate on the north, the Ajmeri Gate on the south - west, the Delhi Gate on the south - east, Turkman Gate on the south and the Nigambodh Gate on the north - east, all of which express vividly the splendor of the city . All the gates are located within a radius of 5--6 km (3.1--3.7 mi) in the present day Old Delhi . The Lahori gate on the Northeast, in the old city, was demolished (some remnant walls are seen at the crossing as may be seen in picture) and the area converted into the present day Lahori Bazar . The gates have a square plan with high arched openings, except for low height of the Nigambodh gate, and two openings--one for entry and another for exit--of the Kashmiri gate . The names of all the gates, which existed during Shahajahan's time are the Dilli Darwaza (also known as Delhi Gate), Kabuli Darwaza, Raj Ghat Darwaza, Khizri Darwaza, Nigambodh Darwaza, Kela ke Ghat ka Darwaza, Lal Darwaza, Kashmiri Darwaza, Badar Darwaza, Patthar Khati Darwaza, Lahori Darwaza, Ajmeri Darwaza and Turkuman Darwaza . </P> <P> The names of the wicket gates or windows (now none exist) through which people entered and exited from the old fort city were: </P>

Known as bada darwaza western entrance to which fort in delhi