Concept:Purana Qila, meaning "Old Fort," is one of the oldest forts in India and is located in the national capital, Delhi.
Explanation:The fort was started by Mughal emperor Humayun in 1533 as part of his new city, Dinpanah.
After Sher Shah Suri defeated Humayun, he captured the fort, renamed it Shergarh, and added more structures.
It lies on the banks of the Yamuna River and is believed by historians to be the site of ancient Indraprastha from the Mahabharata.
Key structures include the Qila-i-Kuhna Mosque (built by Sher Shah Suri) and the Sher Mandal tower, where Humayun later died.
The fort has three main gateways: Bara Darwaza, Humayun Darwaza, and Talaqi Darwaza.
Archaeological excavations have found artifacts from the Painted Grey Ware culture and later periods, showing over 2,500 years of habitation.
Today, Purana Qila is a major cultural landmark and hosts a light-and-sound show about Delhi's history.
Answer:A. Delhi