The Taj Mahal incorporates and expands on design traditions of Persian and earlier Mughal architecture. Specific inspiration came from successful Timurid and Mughal buildings including the Gur-e Amir (the tomb of Timur, progenitor of the Mughal dynasty, in Samarkand), Humayun's Tomb which inspired the Charbagh gardens and hasht-behesht (architecture) plan of the site, Itmad-Ud-Daulah's Tomb (sometimes called the Baby Taj), and Shah Jahan's own Jama Masjid in Delhi. While earlier Mughal buildings were primarily constructed of red sandstone, Shah Jahan promoted the use of white marble inlaid with semi-precious stones. Buildings under his patronage reached new levels of refinement.
The tomb is the central focus of the entire complex of the Taj Mahal. It is a large, white marble structure standing on a square plinth and consists of a symmetrical building with an iwan (an arch-shaped doorway) topped by a large dome and finial. Like most Mughal tombs, the basic elements are Persian in origin.
The base structure is a large multi-chambered cube with chamfered corners forming an unequal eight-sided structure that is approximately 55 meters (180 ft) on each of the four long sides. Each side of the iwan is framed with a huge pishtaq or vaulted archway with two similarly shaped arched balconies stacked on either side. This motif of stacked pishtaqs is replicated on the chamfered corner areas, making the design completely symmetrical on all sides of the building. Four minarets frame the tomb, one at each corner of the plinth facing the chamfered corners. The main chamber houses the false sarcophagi of Mumtaz Mahal and Shah Jahan; the actual graves are at a lower level.