answer: Pilgrims join processions of hundreds of thousands of people, who simultaneously converge on Mecca for the week of the Hajj, and perform a series of rituals: Each person walks counter-clockwise seven times around the Ka'aba , the cube-shaped building which acts as the Muslim direction of prayer , runs back and forth between the hills of Al-Safa and Al-Marwah , drinks from the Zamzam Well , goes to the plains of Mount Arafat to stand in vigil, and throws stones in a ritual.