Qutub-ud-din Aibak laid the foundation for Qutub Minar in 1199 AD and his successor and son-in-law Shamsu'd-Din- Iitutmish completed the structure by adding three more stories. Standing at 72.5 meters, it is the highest stone tower in India. Its base diameter is 14.3 meters and its top diameter is 2.7 meters. It has 379 steps leading to its top story. The lower three stories are made using red sand stone and the top two with marble and sand stone.
There are various stories being told about the reason the Qutub minar was built. Some say that it was constructed as tower of victory to declare the might of Islam. Some others have the view that it might have been used as a tower for defense. The inscriptions at the base of the minaret tell that Firoz Shah Tughlak (AD 1351-88) added the last story in 1368. It is also believed that Sikandar Lodhi(AD 1489-1517) and Major R. Smith (1829) have undertaken several repair and restoration works on the tower. There are a numerous other Arabic inscriptions on the tower telling the history of Qutub.
Other structures in the Qutub complex include:
Tomb of Iitutmish, which was constructed in 1235 AD. The tomb is made up of red sandstone and it describes the Arabic architectural patterns.
Alai Minar, which stands north to Qutub Minar was constructed by Alaud-Din-Khalji with an intention to make it twice the size of Qutub. But he could complete only one storey and the work was abandoned after his death. Alai Minar is 25meters in height.
Quwwat-ul-Islam, a mosque constructed by Qutub-ud-din in 1198 also stands in the Qutub complex.
A famous Iron Pillar, which was erected in the 4th Century AD, is located in the courtyard of Quwwat-ul-Islam. It raises to a height of 7 meters and weighs more than 6 tons. The Sanskrit inscriptions on the pillar tells that it is erected as a flagstaff in honour of hindu god Vishnu and the memory of Chandra Gupta. It is made up of 98% wrought iron and it stood the test of time of more than 1600 years with our rust or decomposition. This proclaims the metallurgical excellence of ancient India.
There are many other installations like madrassas, graves, tombs, mosques in the vicinity of Qutub Minar.
Interestingly Qutub Minar is the most visited tourist spot in Delhi.