The Taj Mahal in Agra is a white marble mausoleum commissioned in 1632 by the Mughal emperor Shah Jahan to house the tomb of his favorite wife, Mumtaz Mahal. Regarded as the finest example of Mughal architecture, it blends Persian, Islamic, and Indian styles. The central dome is surrounded by four minarets that were intentionally built leaning slightly outward; this design ensures that in the event of an earthquake, the towers would fall away from the main tomb rather than on it. The marble is inlaid with semi-precious stones using a technique called 'pietra dura.' Over 20,000 artisans and 1,000 elephants were involved in its construction, which took nearly 22 years to complete. The structure changes color depending on the time of day, appearing pinkish in the morning, milky white in the evening, and golden under the moon.