<Tr> <Td_colspan="2"> Location of Qutub Minar in India </Td> </Tr> <P> The Qutub Minar, also spelled as Qutab Minar, or Qutb Minar, is the tallest minaret in the world made up of bricks . The minaret forms a part of the Qutab complex, a UNESCO World Heritage Site in the Mehrauli area of Delhi, India . Qutub Minar is a 73 - metre (239.5 feet) tall tapering tower of five storeys, with a 14.3 metres (47 feet) base diameter, reducing to 2.7 metres (9 feet) at the top of the peak . It contains a spiral staircase of 379 steps . Its design is thought to have been based on the Minaret of Jam, in western Afghanistan . </P> <P> Qutab - Ud - Din - Aibak, founder of the Delhi Sultanate, started construction of the Qutub Minar's first storey around 1192 . In 1220, Aibak's successor and son - in - law Shamsuddin Iltutmish completed a further three storeys . In 1369, a lightning strike destroyed the top storey . Firoz Shah Tughlaq replaced the damaged storey, and added one more . Sher Shah Suri also added an entrance to this tower while he was ruling and Humayun was in exile . </P> <P> The Minar is surrounded by several historically significant monuments of the Qutab complex, including Quwat - ul - Islam Mosque, which was built at the same time as the Minar, and the much older Iron Pillar of Delhi . The nearby pillared Cupola known as "Smith's Folly" is a remnant of the tower's 19th century restoration, which included an ill - advised attempt to add some more stories . </P>

Who started the construction of qutab minar at delhi