Pilgrims assemble on the 70-metre-high (230-foot) hill and its surrounding plain for hours of prayers and Koran recitals, staying there until the evening.
After sunset they head to Muzdalifah, halfway between Arafat and Mina, where they gather several dozen pebbles so they can perform the symbolic "stoning of the devil".
The last major ritual of the hajj is back at Mina, where pilgrims throw seven stones at each of three huge concrete walls representing Satan.
The ritual is an emulation of Abraham's stoning of the devil at the three spots where it is said Satan tried to dissuade him from obeying God's order to sacrifice his son, Ishmael.
After the first stoning, the Eid al-Adha feast of sacrifice begins, marking the end of the hajj.
The pilgrims can then change back into normal clothing, returning to circumambulate the Kaaba and complete their stone-throwing rituals before heading home.
Sheep are slaughtered, in reference to the lamb that God provided for sacrifice instead of Ishmael, in a ceremony that is held at the same time around the world.
Men then shave their heads or trim their hair while women cut a fingertip-length off their locks.
The hajj is the last pillar of Islam. The four other essential pillars are: profession of the faith; daily prayers; alms-giving and fasting from dawn to dusk during the holy month of Ramadan.
