Not far from the Taj Mahal is the Red Fort of Agra, built in 1565 by Akbar, the thirdMughal emperor, to protect the palace. Behind the 2.5km walls stand the palaces of kings and queens, meeting halls, an audience hall, mosques and the palace of Shah Jahan,who built the Taj Mahal. His residence was made of white marble, for which he had apreference, unlike the red brick of other buildings in the palace. Only 25% of the royal residence is open to the public. The remaining 75% is a restricted zone that belongs to the army.