Once a year, Muslims of every ethnic group, colour, social status, and culture gather together in Mecca and stand before the Kaaba praising Allah together.
It is a ritual that is designed to promote the bonds of Islamic brotherhood and sisterhood by showing that everyone is equal in the eyes of Allah.
The Hajj makes Muslims feel real importance of life here on earth, and the afterlife, by stripping away all markers of social status, wealth, and pride. In the Hajj all are truly equal.
The Hajjis or pilgrims wear simple white clothes called Ihram. During the Hajj the Pilgrims perform acts of worship and they renew their sense of purpose in the world.
Mecca is a place that is holy to all Muslims. It is so holy that no non-Muslim is allowed to enter.
For Muslims, the Hajj is the fifth and final pillar of Islam. It occurs in the month of Dhul Hijjah which is the twelfth month of the Islamic lunar calendar. It is the journey that every sane adult Muslim must undertake at least once in their lives if they can afford it and are physically able.
Four thousand years ago the valley of Mecca was a dry and uninhabited place.
Muslims believe the Prophet Ibrahim (Abraham) was instructed to bring his wife, Hajira (Hagar) and their child Is'mail to Arabia from Palestine to protect them from the jealousy of Ibrahim's first wife Sarah.
Allah told the Prophet Ibrahim to leave them on their own, and he did so, with some supplies of food and water. However the supplies quickly ran out and within a few days Hajira and Is'mail were suffering from hunger and dehydration.
In her desperation Hajira ran up and down two hills called Safa and Marwa trying to see if she could spot any help in the distance. Finally she collapsed beside Is'mail and prayed to Allah for deliverance.
Is'mail struck his foot on the ground and this caused a spring of water to gush forth from the earth. Hajira and Is'mail were saved. Now they had a secure water supply they were able to trade water with passing nomads for food and supplies.
After a while the Prophet Ibrahim returned from Palestine to check on his family and was amazed to see them running a profitable well.
The Prophet Ibrahim was told by Allah to build a shrine dedicated to him. Ibrahim and Is'mail constructed a small stone structure - the Kaaba or Cube - which was to be the gathering place for all who wished to strengthen their faith in Allah.
As the years passed Is'mail was blessed with Prophethood and he gave the nomads of the desert the message of surrender to Allah.
After many centuries, Mecca became a thriving city thanks to its reliable water source, the well of Zam Zam.
Gradually, the people began to adopt polytheistic ideas, and worship spirits and many different gods. The shrine of the Prophet Ibrahim was used to store idols.
After many years, Allah told the Prophet Muhammed that he should restore the Kaaba to the worship of Allah only.
In the year 628 the Prophet Muhammed set out on a journey with 1400 of his followers. This was the first pilgrimage in Islam, and would re-establish the religious traditions of the Prophet Ibrahim.
In the morning you return to Mina and throw the stones at pillars called Jamraat. These represent the devil. Then a sacrifice called a Qurbani should be made in which a lamb or sheep is slaughtered and the meat distributed among the poor. After this, men's heads are shaved and women cut a lock of their hair.
Then return to Mecca and make a Tawaf (this is the ritual of walking around the Ka'aba seven times). Then it's back to Mina for 3 or 4 days, stoning the pillars each day.
Finally do a farewell Tawaf in Masjid-al Haram on the twelfth day of the month of Dhul Hijjah, ask Allah's forgiveness, make du'aand the Hajj is finished.
Many people then go to the Prophet's Mosque in Medina, but this is optional.
A man who has completed the Hajj is called a Hajji, a woman who has completed it is called a Hajjah.
At the end of the Hajj, Muslims from all over the world celebrate the holiday known as the Eid ul Adha or Festival of the sacrifice.
This festival commemorates the obedience of the Prophet Ibrahim when he was ordered to sacrifice his son Is'mail.
Ibrahim proved his love and devotion to Allah by showing his willingness to kill his beloved son if Allah wished it. In the end Ibrahim did not have to kill his son as Allah gave him a ram to sacrifice instead.