In Pictures: Hajj 2015

Roughly 3 million people from around the world are expected to converge at the Kaaba, in Mina and other nearby areas for the Hajj, which lasts about five days. [Mosa ab Elshamy/AP]

The Hajj pilgrimage 2015 takes place in Mecca from 22 to 26 September. The pilgrimage is one of Islam's five pillars, it has to be performed at least once in one's life if he or she can afford it. [Amel Pain/EPA]

Muslim pilgrims circumvent around the Kaaba at the Masjid al-Haram Mosque, Islam's holiest site, two days before the Hajj pilgrimage, in Mecca, Saudi Arabia. [Amel Pain/EPA]

A Muslim pilgrim couple take a selfie on a rocky hill called the Mountain of Mercy, on the Plain of Arafat, near the holy city of Mecca. [Mosa ab Elshamy/AP]

Mina is the world's largest tent city. [Mosa ab Elshamy/AP]

A Muslim pilgrim on Mount Mercy on the plains of Arafat. [Ahmad Masood/Reuters]

Saudi Arabia has deployed 100,000 security personnel to oversee the annual Islamic Hajj pilgrimage that begins on Tuesday. [Mosa ab Elshamy/AP]

A Muslim pilgrim uses her mobile phone to light up as she reads from the Quran after visiting Hera cave, where Muslims believe Prophet Mohammad received the first words of the Koran through Gabriel, at the top of Mount Al-Noor. [Ahmad Masood/Reuters]

Muslim pilgrims pray on Mount Mercy on the plains of Arafat. [Ahmad Masood/Reuters]

The visit to Hirat Grotto is not part of the Hajj pilgrimage, but a tradition some pilgrims like to carry on with to deepen their spiritual experience. [Amel Pain/EPA]

Mount Arafat, marked by a white pillar, is where Islam's Prophet Muhammad is believed to have delivered his last sermon to tens of thousands of followers some 1,400 years ago, calling on Muslims to unite. [Mosa ab Elshamy/AP]