Monday for the high point of the annual hajj, praying for an end to disputes and bloodshed.
Officials said they expected around 1.5 million pilgrims to descend on the site, where they were to offer prayers and later in the day to listen to the annual sermon from Saudi top cleric Sheikh Abdulaziz al-Sheikh.
Helicopters hovered overhead and thousands of troops stood guard to organise roads flooded by men, women and children streaming towards Mount Arafat.