It was the second of the seven cities of medieval Delhi built around 1303.
Siri has seven gates. Only the southeastern gate exists.
According to the legend of Ala-ud-din’s war exploits, the name Siri given to the Fort was because the foundation of the fort was built on the severed heads (‘Siri’ in Hindi means “head”) of about 8,000 Mongol soldiers killed in the war.
A water reservoir at Hauz Khas provided water to Siri,
The destruction of the Fort is attributed to the local rulers who removed the fort's stones, bricks and other artifacts for their own buildings. In particular, Sher Shah Suri took material from Siri to build his own city.
The battered walls of the fort had a wider base on the outside. A protected passage was provided within the battered walls (now seen in ruins as pictured)