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 
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. 

Excavation of Grey Ware Pottery
Several excavations have taken place in the Purana Qila in an attempt to prove, or disprove as the case may be, whether it is indeed the site of Indraprastha or not. Diggings have yielded Painted Grey Ware pottery which has been dated to 1000BC. Similar stuff has been noticed in other sites associated with the epic Mahabharata as well, which seem to conclusively prove that this indeed was the place where Indraprastha once flourished. These excavation have also thrown up material, like coins, associated with the Gupta (about 4-5th century AD) and post-Gupta ages (700-800AD) of Indian history as well. 

Qila-i-kuhna Masjid
One of the most fascinating buildings, and also one of the few that still survive, in the Purana Qila is the Qila-i-kuhna masjid. Sher Shah Suri built it in 1541 (also see History) and he was obviously out to make a definite style statement. 
The mosque is quite a place; its prayer hall measures 51.20m by 14.90m and has five doorways with the 'true' horseshoe-shaped arches. Apparently the idea was the build the whole mosque in marble, but the supply ran out and red sandstone had to be used instead. But the builder used the material at hand very skillfully and the result is quite spectacular – the red sandstone and the marble contrast beautifully with each other to give the mosque a very distinctive air. The mihrabs (prayer niches) inside the mosque are richly decorated with concentric arches. From the prayer hall, staircases lead you to the second storey where a narrow passage runs along the rectangular hall. The central alcove is topped by a beautifully worked dome. In the courtyard at one time there was a shallow tank, which had a fountain. The mosque has an inscription which says 'As long as there are people on this earth, may this edifice be frequented, and people be happy in it.' A noble thought – amen to it.

The ruins of this fort are located on a small hill which once stood on the banks of the Yamuna river. Legend has it that the fort marked the site of Indraprastha, the magnificent capital of the Pandavas, though the construction was carried out by Sher Shah Suri any time between 1538 to 1545 A.D.The structure houses a mosque which has a double-storeyed octagonal tower. It is said that the Mughal King, Humayun, fell from the tower accidently and died. At the foot of the hill is a lake where the Delhi Tourism has arrangements for boating and also a sound and light show. 
The location of Purana Qila is not new to history, as the earliest reference to this site is made in the Hindu epic, Mahabharata. Recent excavations at the fort site have yielded painted grey ware pottery which dates back to 1000 B.C.The fact that until 1913 there was a village within the fort called Indrapat gives credence to the belief that Purana Qila was built on the ruins of Indraprastha. The walls of the fort are 18 metres high at some points and there are groups of holes arranged in patterns on the walls which were apparently meant to be nesting spaces for birds. 
The fort has three gates- Humayun Darwaza, Talaqi Darwaza and Bara Darwaza, through which one can enter the fort today. Inside the fort is the Kuhna Masjid built by Sher Shah in 1541 and is considered to be a masterpiece of architecture. The inner west wall of the building has five arched openings which are richly ornamented in white and black marble. On a marble slab inside the mosque is an inscription which when translated reads: ' as long as there are people on this earth, may this edifice be frequented and people be cheerful and happy in it'.