Agra Fort is a historical fort in the city of Agra in India. It was the main residence of the emperors of the Mughal Dynasty till 1638, when Mughal capital was shifted from Agra to Red Fort in Delhi. It is also a UNESCO World Heritage site and is about 2.5 km northwest of its more famous sister monument, the Taj Mahal. The fort can be more accurately described as a walled city.The Agra Fort won the Aga Khan Award for Architecture in 2004. India Post issued a stamp to commemorate this event