Agra is famous for both the Taj Mahal and The Red Fort. The Taj Mahal is one of the most famous buildings in the world. It is a white marble mausolem built by Mughal Emporer Shah Jahan in memory of his third wife, Mumtaz Mahal. It is recognised as the jewel of Muslim architecture in India. Agra Fort is a walled city built initially as a military establishment. It is situated on the banks of the Yamuna River and is more commonly known as Red Fort due to the red sandstone used in its construction.