The principal mosque of the Agra Fort Complex, Jami Mosque was completed in 1648 by Jahanara, the elder daughter of Shah Jahan.  It is raised upon a platform on the northwestern side of the Fort.  The Mosque is of red sandstone highlighted with white marble.  The plan features a large square courtyard enclosed by three narrow  arcades and a prayer hall. Axial gates punctuate the three arcade wings.  The prayer hall is topped by three domes decorated with a zigzag pattern, and flanked by two tall, domed minarets. The eastern wing, destroyed by the British during the Indian Mutiny in 1857, is replaced by a railway line that separates the Mosque from the Delhi gate of the Fort Complex.
Source: 
Koch, Ebba. 1991. Mughal Architecture. Munich: Prestel, 118-121.
Tillotson, GHR. 1990. Mughal India. San Francisco: Chronicle Books, 85.