Red Fort Delhi
¤ The Construction
Built during the reign of Shah Jahan, the Lal Qila (or Red Fort) has been a mute witness to innumerable conspiracies, scandals, battles..... Completed in a span of nine years, it cost about ten million rupees , with about half the sum going towards the building of palaces.
The fort is octagonal in shape, like most Islamic buildings in India. The north of the fort is connected to the smaller Salimgarh fort. The Red Fort is an intimidating structure. It measures 900m by 550m, with its rampart walls covering a perimeter of 2.41km. It towers at a height of 33.5m. On the outside, you can still see the moat that was originally connected with the Yamuna River.

Purana Qila (Old Fort)
¤ Humayun- The Mughal Emperor Costructed The Fort
When the second Mughal emperor Humayun decided to make a city of his own he decided on the site of the ancient city of Indraprastha. Humayun was quite a scholar with a fine grasp on such matters and so it is certain that the site was chosen deliberately. When his Sher Shah Suri overthrew him, he destroyed most of Dinpanah (refuge of the faithful) as the city of Humayun was called to make way for his own Dilli Sher Shahi or Shergarh. Incidentally, Humayun was probably the only emperor in history who built a city in Delhi and did not give it his own name – this was typical of Humayun's rather sophisticated and dreamy character. The Layout of The Massive Colossal

Purana Qila
In plan the Old fort, now simply called Purana Qila by Delhites, is irregularly orbital. The walls of the immense Qila tower down on the road that takes one to Pragati Maidan from the height of 18m, and run on for about 2km. It has three main gates – the Humayun darwaza, Talaqi darwaza and Bara darwaza (which one uses to enter the fort today). The double-storeyed gates are quite huge and are built with red sandstone. of all the gates entry was forbidden from Talaqi (forbidden) darwaza, the northern gate. It is not clear why this was so. Other Attractions of The Fort
Sher Shah Suri and his successor could not complete the city, and when Humayun defeated Sher Shah's son to take back his city, he did not deal with Dilli Sher shahi as the latter had done with Dinpanah. In fact the Mughal emperor very handsomely completed the city and even used several of the buildings like the Sher Mandal, a rather pretty two-storeyed octagonal building. Humayun used this as his library and, then tripped to his death from its steps.

Tughlaqabad Fort
¤ Fort Stands In Isolation
Tughlaqabad Fort'Ya base gujjar, ya rahe ujjar.' (May [this city] be the abode of nomads or remain in wilderness.)
These words, with which the great Sufi saint Hazrat Nizamuddin Auliya cursed Ghiyas-ud-din's city, seem to still echo all over the ghostly ruins of Tughlaqabad. The citadel frowns down ominously like some Gothic palace all over the Qutub-Badarpur road and seems to prefer its splendid isolation. Which is of course not exactly what Ghiyas-ud-din Tughlaq had in mind when he started out building it. It would have broken the old sultan's heart if he had seen just how swiftly the saint's curse went into action; soon after his death in fact.

Nai ki Kot--The Fortresses of Adilabad
South of Tughlaqabad and once connected to it by a causeay is the fortress of Adilabad, which was built by Muhammad-bin-Tughlaq. In plan it is a smaller version of Tughlaqabad, with the trademark sloping walls of huge stone. Inside Adilabad was the legendary Qasr-i-hazaar satun or the Palace of a thousand pillars, which seems to have been a really popular idea back then (see Bijai Mandal). The palace had a huge audience hall, which was built on columns of varnished wood. Towards the southern gateway you can still see a vaulted corridor which used to be flanked by guardrooms. Adilabad has all the marks of a fine Tughlaq building with that style's typically austere walls, bare surfaces, corbeled arches and crenellation.
Outside the fortress towards the east is the Barber's fort. It is not known whether a barber actually ever lived in the tiny fortress of Nai ka kot (barber's fort), but it seems Ghiyas-ud-din certianly did. He used this place as a temporary residence when Tughlaqabad was coming up. It is built in the same style as Adilabad.