The Taj Mahal situated at Agra, is a world famous building made up of white marble. It was built by Mughal king Shah Jahan in the memory of his wife Mumtaz Mahal. It is said that Mumtaz once saw a beautiful white building in her dream and narrated it to her husband. Thus, the plan of Taj Mahal was based on her dream. Shahjahan built it as a tomb for Mumtaz. 20,000 men took 20 years to construct this building. It was built in the 16th or 17th century CE. Taj Mahal is the only Indian building to be one of the 7 wonders of the world.