The gathering in one place of Muslims from across the globe is seen as a means of sending across the message of Muslim unity to the entire world.
“It’s the dream of every Muslim to come here to Mecca,” Frenchman Soliman Ben Mohri, a 53-year-old Muslim, said. “It’s the ultimate journey.”
Each and every able-bodied Muslim, male or female, is required to complete the Hajj pilgrimage at least once in their lifetime if they also have the sufficient financial capacity to do so.
Most of the pilgrims began moving on Sunday from Mecca to the nearby Mina, where they will spend the night in fire-resistant tents.
Thousands of buses and vehicles carrying the pilgrims lined the eight-kilometer road from Mecca to Mina. Many pilgrims made the journey walking under the scorching heat of the sun.
A tragic human crush during the Hajj rituals in 2015 killed thousands of pilgrims in Mina.
Saudi authorities gave an initial tally of 770 deaths and then stopped updating that figure, even as official counts from individual countries whose nationals had died in the incident rose to the thousands in total.
On Monday, more than two million people from around the world began ascending Mount Arafat for the pinnacle of the annual Hajj.
The ritual marks a sea of worshipers scaling the rocky hill southeast of the holy city of Mecca for a day of prayers and reflection where Muslims believe Prophet Mohammed (Peace be upon Him) delivered his final sermon.
During Hajj, pilgrims retrace the steps of Prophet Muhammad's last pilgrimage before his passing in 632 CE.
They wear the same - two towels wrapped at the waist and shoulders for men, and a simple garment not covering the face for women. The clothes symbolize equality among all Muslims as they come to face God on the holiest pilgrimage.