INDIA CROSSING THE RIVER GANGES The Taj Mahal complex is bounded on three sides by crenellated red sandstone walls; with the river-facing side left open. Outside the walls are several additional mausoleums; including those of Shah Jahan's other wives; and a larger tomb for Mumtaz's favorite servant. These structures; composed primarily of red sandstone; are typical of the smaller Mughal tombs of the era. The garden-facing inner sides of the wall are fronted by columned arcades; a feature typical of Hindu temples which was later incorporated into Mughal mosques. The wall is interspersed with domed chattris; and small buildings that may have been viewing areas or watch towers like the Music House; which is now used as a museum.