The Taj Mahal has several red sandstone buildings on two sides. They are the mausoleums of his other wives, as Mumtaz Mahal and Shah Jahan were buried in the main white marble tomb. A mosque and a darwaza (gateway) protect and lead to the Taj from the sides. Its towers are angled to fall away from the main tomb, in case of an earthquake. Built in 17th century and destined to remain unparalleled.