With its towering walls and dramatic gateways, Purana Qila was constructed by Afghan ruler Sher Shah (1538–45), who briefly seized control of Delhi from the emperor Humayun, and the monumental gatehouse opens onto a peaceful garden studded with ancient monuments. The graceful octagonal, red-sandstone Sher Mandal was used by Humayun as a library; it was a fall down its stairs that ended his reign, and life, in 1556. Beyond is the intricately patterned Qila-i-Kuhran Mosque (Mosque of Sher Shah).

Across busy Mathura Road are more relics from the city of Shergarh, including the Khairul Manazil mosque, still used by local Muslims. A popular boating lake has been created from the former moat, with pedalos for hire. There’s a sound & light show (in English 8.30pm February to April, September and October; 9pm May to August; and 7.30pm November to January) at the fort.

The free Ananya Dance Festival takes place here in October.