As part of the ‘facial’ treatment for the monument, lime-rich clay will be plastered over the affected areas of the monument and left overnight. As the mud begins to dry, it will be washed away, hopefully with the grime that coats the monument.The maiden mud-pack treatment of the Taj took place in 1994, the second in 2001 and the last such treatment was given to it in 2008.The last treatment cost Rs 10.4 lakh. Over two experts had carried out the work.The Taj Mahal was built by the Mogul Emperor Shah Jahan between 1632 and 1654 for his favourite wife, Mumtaz Mahal. It houses their graves. The Taj complex has a mosque as well as several other graves of lesser Mogul royalty.