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.

You probably had no idea that over two billion people around the world are currently celebrating one of the most significant religious holidays on the planet. While you’re going about your regular Friday routine, millions of Muslims are engaged in prayers, family gatherings, and religious rituals that have been happening for over a thousand years.