Pilgrims dressed in white spend their day in preyers and reflection.

More than two million Muslim pilgrims started Monday to pour into the holy Mount of Arafat and its surrounding plain on the peak day of the world\'s largest annual pilgrimage, the Hajj.

By the dawn, tens of thousands of pilgrims had already set off from their camps in the valley of Mina, some 10 kilometers northwest of Arafat. 

Saudi authorities said permits have been granted to 1.8 million foreign pilgrims, with a further 200,000 or so issued to pilgrims from within Saudi Arabia and from neighboring Gulf States, in addition to other unregistered pilgrims.

By sunrise, the Jabal al-Rahma, or the Mount of Mercy -- the hightest point in Arafat, pilgrims dressed in white garments climbed to the top to take up positions on the hills\' slippery rocks and spend the day in prayers and reflection.

The granite hill, rising some 60 meters from the plain with no more than 200 meters length and a similar width, is topped with a four-meter pillar, said to represent the spot where the holy prophet of Islam, Mohammed (PBUH), delivered his final hajj sermon.

After sunset, pilgrims move to Muzdalifah, half-way between Mount Arafat and Mina, to spend the night.

On Tuesday, they return to Mina after dawn prayers for the first stage of the stoning of the devil and to make the ritual sacrifice of an animal, usually a lamb.

On the remaining three days of the hajj, the pilgrims continue the ritual stoning before performing the circumambulation of the Kaaba shrine in Mecca and then heading home.