the red fort was originally referred to as "qila-i-mubarak" (the blessed fort), because it was the residence of the royal family. the layout of the red fort was organised to keep and integrate this site with the salimgarh fort. the planning and aesthetics of the red fort represent the high point in mughal creativity which happened during the reign of emperor shah jahan. this fort has had many additions after its construction by emperor shah jahan. it is a world heritage site. it is made out of red sandstone.