Large numbers of Muslims converge once a year on Saudi Arabia to unite in a series of religious rituals and acts of worship as they perform the Hajj, the pilgrimage that is one of the pillars of Islam.

Millions of Muslims from all over the world have converged on Mecca in Saudi Arabia to partake in Islam's annual Hajj pilgrimage.

Muslims from around the world travel to participate in the Hajj each year, an annual sacred pilgrimage to the holy city of Mecca in Saudi Arabia. The big picture: The deeply spiritual journey, which every able-bodied and financially capable Muslim is expected to undertake at least once,