The annual journey of Muslims from all over the world to the holy city of Mecca in modern-day Saudi Arabia is known as the Hajj and is considered one of the "five pillars" of Islam.
The Kaaba, a stone building covered in black silk at the centre of the Grand Mosque in Mecca, is said to have been constructed by the Prophet Abraham in biblical times, according to Islamic legend.
It happens at the same time every year, in the Islamic calendar's sacred month of Dhul Hijjah, which is the twelfth month. Depending on the sighting of the moon, the Hajj begins on the eighth of Dhul Hijjah and lasts for about five to six days. Eid al-Adha, a four-day festival, is ushered in by Muslims all around the world when they see the new crescent moon.
One of the fifth pillars of Islam, the Hajj, is a sacred journey that every Muslim is obligated to perform at least once in their lives. Millions of Muslims from all over the world visit Makkah, Saudi Arabia, each year to perform the Hajj.
What occurs during Hajj?
While on pilgrimage, Muslims perform a number of essential rites.
Men must wear two sheets of white cloth, which must be worn in a precise manner. Women must dress traditionally and cover their heads but not their faces. These garments represent the equality of all Muslims before Allah.
During the first part of Hajj, Muslims walk around the Ka'bah seven times in an anti-clockwise direction. This is called as Tawaf and is done to demonstrate that all Muslims are equal.
The next ceremony requires Muslims to run seven times between two hills, Safa and Marwah. Muslims believe that Hagar, the prophet Abraham's wife, did this while looking for water for her young son Ishmael. Ishmael is said to have struck his foot on the ground, causing a spring of water known as Zamzam to shoot up. It is customary for pilgrims to bring water from Zamzam with them when they return home.
Pilgrims travel to the Arafat plain. This is where the Prophet Muhammad delivered his farewell speech, and Muslims come here to pray to God for forgiveness and guidance.
According to the News more than two million Muslims will participate in this week's Hajj pilgrimage to Saudi Arabia's holy city of Mecca.
The greatest Hajj pilgrimage in history will take place this year, a Saudi Ministry of Hajj and Umrah official told Al Jazeera. The Hajj, one of the biggest religious gatherings on earth, is now fully operational after years of restrictions brought on by pandemics.