Taj Mahal 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
Taj Mahal in the event of an earthquake. In 2011, it was reported that some predictions indicated that the tomb could collapse within 5 years. Small minarets located at two of the outlying buildings were reported as damaged by a storm on April 11, 2018. The Taj Mahal attracts a large number of tourists. UNESCO documented more than 2 million visitors in 2001, which had increased to about 7–8 million in 2014. A two-tier pricing system is in place, with a significantly lower entrance fee for Indian citizens and a more expensive one for foreigners. In 2018, the fee for Indian citizens