Built by Iltutmish for his eldest son Nasiruddin Mahmud, who died before him. The tomb is regarded to be the oldest Islamic Mausoleum in India. It stands alone amidst the rugged plains off the Kishangarh – Mehrauli Road, near Vasant Kunj.
Adorned with corbel arches, the tomb is one of the few Islamic structures to be constructed before the arrival of the true arch in the Indian subcontinent. It has been serving as a mosque over the past centuries.