The Entrance gate of Siri Fort
As far as I know, Siri Fort in Delhi had the Palace of Thousand Pillars. Only the embattlements have left of the entire fort. Alauddin Khilji established Hauz Khas fort in the year 1284. The word comes from urdu word 'Hauz' which means Pond. The emperor commissioned a very large pond or tank in this area for the use of the inhabitants of Siri Fort, the second city of Delhi. Earlier it was named as 'Hauz-i-Alai' after the name of emperor Alauddin Khilji. Firuz Shah Tughlaq later ordered to clean the tank, which was full of silt. He also built royal baths on the southern side of the tank.