Qutb Minar is one of Delhi's UNESCO World Heritage Sites.
The Qutb Minar was commissoned by Qutbu l-Din Aibak, the first sultan of Delhi, in 12th century.
The spire was used to issue Adhan, the Muslim call to prayer.
The complex was originally a complex of Jain temples that were destroyed after Delhi was conquered by Islam.
The Qutb Minar is covered in verses from the Qu'ran. You can find out more about this ancient monument at http://www.easytoursofindia.com/qutab_minar.htm