Muslim faithful from around the world have flocked to the holy city of Mecca for the annual Hajj pilgrimage.
On Monday they headed to Mount Arafat, outside Mecca, and began climbing to perform the central rite of Hajj.
The rite of Wukuf, or standing, before sunset on Arafat is the high point of the Hajj, without which the pilgrimage would be deemed incomplete.
The Hajj pays tribute to the prophet Muhammad's last sermon on Mt Arafat in 632AD.
Muslims have come from almost every country in the world.
Young and old have come to Mecca, which is revered as the most holy site in Islam.
More than two million people marched to the city on Sunday for the formal beginning of the pilgrimage.
The Hajj is known as the fifth pillar of Islam, and is a journey all able-bodied Muslims must undertake during their lives.
Authorities have taken extra precautions - such as the deployment of air ambulances - to keep the crowds safe.