15 Photos From The Hajj Pilgrimage In Mecca

A Muslim pilgrims poses for a photograph as he climbs Noor Mountain to Hiraa cave, where Prophet Muhammad received his first revelation from God to preach Islam, on the outskirts of Mecca.

Muslim Pilgrims attend Friday afternoon prayers outside the Grand Mosque in the holy city of Mecca.

Muslim pilgrims arrive for the Maghrib late afternoon prayer at the Grand Mosque in Mecca.

A Muslim pilgrim prays atop Noor Mountain outside the Hiraa cave, where Prophet Muhammad received his first revelation from God to preach Islam, on the outskirts of Mecca.

Pilgrims queue atop Noor Mountain outside the Hiraa cave.

Pilgrim heads towards Mount Hira where Prophet Mohamed is believed to have received the first verses of Quran from the Angel Gabriel in Mecca.

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.

All able-bodied Muslims are required to perform the pilgrimage once in their lives.

Muslim pilgrims circle counterclockwise at Islam's holiest shrine, the Kaaba, at the Grand Mosque in Mecca.

Muslim pilgrims pray at the Kaaba.

A pilgrim cries while praying in Mecca.

In Mecca, the annual pilgrimage began with over millions of faithful gathering to call out in Arabic: "Here I am, God, answering your call. Here I am."

Prayers at the pilgrimage are aimed at ultimately erasing past sins.

Pilgrims walk outside the Grand Mosque.