Muslim pilgrims reached to the Mina valley for noon prays in Mecca, Saudi Arabia on Friday. The Hajj will begin on November 5.

Muslims from across the world gathered on this holy city ahead of the annual hajj pilgrimage, many of them with prayers for a peaceful world.

Some 2.5 million people are expected to take part in the five-day event that starts Saturday, Saudi authorities said. The pilgrimage focuses on Makkah, Islam’s holiest site and the birthplace of the Prophet Muhammad  (S.A.W).

The annual Islamic pilgrimage draws three million visitors each year, making it the largest yearly gathering of people in the world.

The Hajj is the pilgrimage to Makkah, Saudi Arabia. It is the largest pilgrimage in the world, and is the fifth pillar of Islam, a religious duty that must be carried out at least once in their lifetime by every able-bodied Muslim who can afford to do so. The Hajj is a demonstration of the solidarity of the Muslim people, and their submission to Allah.

The pilgrimage occurs from the 8th to 12th day of Dhu al-Hijjah, the 12th and last month of the Islamic calendar.

Pilgrims join processions of hundreds of thousands of people, who simultaneously converge on Mecca for the week of the Hajj, and perform a series of rituals: Each person walks counter-clockwise seven times around the Kaaba,  runs back and forth between the hills of Al-Safa and Al-Marwah, drinks from the Zamzam Well, goes to the plains of Mount Arafat to stand in vigil, and throws stones in a ritual Stoning of the Devil. The pilgrims then shave their heads, perform a ritual of animal sacrifice, and celebrate the three day global festival of Eid al-Adha.