Purana Qila - Old Fort

When it was built: 16th century
By whom it was built: Sher Shah Suri
Nature of the building: Fort

Purana Qila - Old Fort in Delhi was constructed in the 16th-century by Sher Shah Suri, the founder of the Sur Dynasty. Mughal Emperor Humayun was defeated by Shah Suri in 1539. Thus after capturing two Mughal strongholds- Delhi and Agra, Shah Suri constructed this fort to defend Delhi from the Mughals. Incidentally, only after Sher Shah Suri died in 1545, Humayaun was able to recapture Delhi and Agra.
Humayun began using Sher Mandal, the octagonal red sandstone tower as his library and observatory later. According to legends, Humayun died after falling down from the steps of this tower and thus the Mughals, later decided to vacate the fort considering it to be ominous. They constructed Lal Qi'lah or Red fort to defend Delhi from foreign invasions.
  -   Purana Qila - Old Fort in Delhi houses the Delhi Zoo, Delhi's largest zoological park, and a boat club.
  -   The Qal'a-I-Kunha Masjid and the Sher Mandal are two important monuments inside the fort.
  -   Qila-i-kuhna Masjid was built by Sher Shah Suri in 1541, which has five doorways with the 'true' horseshoe-shaped arches. Red sandstone and marble were used in contrast to give the mosque a very distinctive look. The mihrabs (prayer niches) are decorated with concentric arches and the central alcove is topped by a beautifully carved dome. The mosque has an inscription which says 'As long as there are people on this earth, may this edifice be frequented, and people be happy in it.' it.
  -   The fort has bastions on the corners and in the western wall.The walls of the Fort tower down on the road for about 2 kilometers and from a height of 18 meters.
  -   It has three main gates - the Humayun darwaza, Talaqi darwaza and Bara darwaza, which are double-storied and built with red sandstone.
  -   Excavations in 1955 have yielded painted Grey Ware pottery dated to 1000BC. Findings like coins associated with the Gupta of 4-5th century AD and post-Gupta ages, have also been found
  -   Sher-Mandal is a double-storeyed octagonal tower of red sandstone that was surmounted by an octagonal pavilion or chhatri. The central chamber is cruciform with recesses on its four sides and the dados of its interior are decorated with glazed tiles, while the upper portion contains incised and painted plasterwork.
  -   There is a lake surrounded by a garden with rows of trees and flower plants, which has paddle-boating facility. Inside the fort too there are lawns