Situated north-west of Qutab Minar, Quwwat – Ul – Islam mosque is one of the oldest mosques built in India. Quwwat – Ul – Islam mosque was built in between 1193 and 1198 A.D. Qutub-ud-din began the construction of this mosque in 1193 but a number of additions and extensions were made over the centuries. The original mosque was built upon a Hindu temple, an inscription over the eastern gateway states that the mosque was built with materials obtained from demolishing ’27 idolatrous temples.’ Initially, this mosque was small, later in 1210 – 1230 A.D, Shamsuddin Iltutmish extended the whole compact area to double and surrounded it with huge walls. In 1300 A.D, Alauddin Khilji increased the area by adding a court to the east and the huge Alai Darwaza gateway.

Iron Pillar : Just adjacent to the Quwwat – Ul – Islam mosque is 7.2 mts high Iron Pillar. The Iron pillar stands in the courtyard of the mosque which has been here even much before the construction of the mosque. Originally the Iron Pillar

Alai Minar : Head north of the Qutab Minar and the Quwwat – Ul – Islam mosque to see the Alai Minar, the unfulfilled dream of Alauddin Khilji. While Alauddin Khilji made additions to mosque he also planned a much more ambitious project. Khilji planned that he would build a second tower of victory just like the Qutab Minar and it would be twice the height of the former. But Alauddin Khilji died during the construction of Alai Minar and the tower could reach only 27 mts high. After Khilji, no one was willing to continue his over-ambitious project and kept the construction confined right at the stage of single floor.

Built by the wife of Humayun, Haji Begum in the mid 16th century, this red sand stone structure is considered to be the predecessor of Taj Mahal. The structure is one of the best example of Mughal Architecture. Humayun's wife is also buried in the red and white sandstone, black and yellow marble tomb. The entry in the complex is free on Fridays.