Today, some 3 million people a year (or around 45,000 a day during peak tourist season) visit the Taj Mahal. Air pollution from nearby factories and automobiles poses a continual threat to the mausoleum’s gleaming white marble façade, and in 1998, India’s Supreme Court ordered a number of anti-pollution measures to protect the building from deterioration. Some factories were closed, while vehicular traffic was banned from the immediate vicinity of the complex