There are two versions of the pilgrimage which are acceptable:
i) Umra (visitation) or lesser pilgrimage. This can be made at any time.
ii) Hajj. This begins in Mecca on certain days in the holy month of Dhu-al Hijja. Before entering the sacred territory around Mecca pilgrims must perform special ablutions, don the ihram (two sheets of seamless white cloth which symbolizes purity) and say prayers. They enter the mosque and walk seven times around the Ka'ba or sacred black stone, which they should try to kiss or at least touch, before drinking at the sacred well called Zamzam. After this a lock of their hair will be cut (pious Muslims may shave their head entirely).
The next day they set off to nearby Mt. Arafat, some 13 miles from Mecca. The next day after that they climb the mountain and offer prayers before stopping at Muzdalifa for the night. The next day they stop at the town of Mina where seven stones must be hurled at the three pillars there in rememberance of how Isma'il drove away the devil.
