Every hour, officials estimate an average of 107,000 pilgrims circle the Kaaba, the black cube at the centre of Makkah's Grand Mosque
The hajj pilgrimage, which started at Islam's holiest sites in Saudi Arabia on Sunday, is one of the world's largest annual gatherings.
Here are key figures:
- More than 2.37 million pilgrims are taking part this year, according to official figures, compared to 1.86 million in 2016 and just 24,000 in 1941.
- Tens of thousands of security personnel, including some 18,000 civil defence employees, are helping safeguard pilgrims, officials say. Thousands of security cameras have been set up along the pilgrimage route.
- Every hour, officials estimate an average of 107,000 pilgrims circle the Kaaba, the black cube at the centre of Makkah's Grand Mosque, which Muslims around the world must face while praying.
- Twenty-five hospitals, 180 ambulances and more than 30,000 health practitioners have been prepped to provide emergency services to pilgrims, according to the hajj ministry.
- Tens of thousands of air-conditioned tents have been set up to house pilgrims as temperatures climb to 44 degrees Celsius (111 degrees Fahrenheit).
- Around 14,000 international and domestic flights have transported pilgrims to the kingdom, according to official figures. Some 21,000 buses have also brought the Muslim faithful to Makkah.
- 16,000 telecommunication towers and 3,000 WiFi zones have been set up to serve pilgrims, the hajj ministry says.
- Saudi Arabia says it plans to hand out eight million copies of the holy Koran in multiple languages to pilgrims along with other religious books.
- The kingdom hopes to welcome 30 million pilgrims annually in the kingdom by 2030. Muslims also travel to Saudi Arabia for the umra pilgrimage, which can be performed at any time of the year.
- Around 54 million pilgrims have attended the hajj over the past 25 years, according to official figures.