Muslim pilgrims visit Heera cave on Jebel al-Noor, Mount of Light, where Muslims believe Prophet Mohammed received the revelation of the Koran, above the city of Mecca, Saudi Arabia on December 5, 2008. More than two million Muslims head to the holy city of Mecca, Saudi Arabia to make the annual Hajj pilgrimage. All fit and financially able Muslims are expected to perform the Hajj at least once in their life. (UPI Photo/Mohammad Kheirkhah)