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 until 1648, when the Mughal capital was shifted from Agra to Delhi. Before capture by the Mughals, it was a walled city held by the Chauhan Rajputs. It is a UNESCO World Heritage Site and lies about 2.5 kilometers northwest of its more famous sister monument, the Taj Mahal. The fort is more accurately described as a walled palatial city built with majestic red sandstone.