This magnificent 14th-century ruined fort, half reclaimed by jungle and gradually being encroached on by villages, was Delhi's third incarnation, built by Ghiyas-ud-din Tughlaq. The sultan poached workers from the Sufi saint Nizam-ud-din, who issued a curse that shepherds would inhabit the fort. However, it's monkeys rather than shepherds that have taken over. There are fantastic emerald-green views. Interlinking underground rooms, which you can explore, were used as storehouses.

　　The sultan’s well-maintained sandstone mausoleum once stood in the middle of a lake, but now is separated from his fallen city by a road. It's included in the entry ticket.

　　The ruins of the fort are fairly deserted, so it's best to visit them in a group; you could easily spend a couple of hours exploring, so you may not wish to visit them alone. It does get hot out here, so bring plenty of water and snacks – there's nowhere to buy anything.

　　To reach the fort, take an autorickshaw from the Govind Puri metro station (₹50). Shared autos (₹10) tend only to take you to the end of Guru Ravi Das Marg, leaving you to walk the final 500m to the entrance.