Saudi Arabia ? Nearly 3 million pilgrims chanting prayers converged Saturday in a valley just outside the holy city of Mecca at the beginning of the 5-day hajj pilgrimage, a lifelong dream for many Muslims.

The pilgrims from about 100 countries left Mecca after completing the first ritual of the hajj by circling the sacred Kaaba stone structure seven times inside the Grand Mosque, which Muslims all over the world face during their five daily prayers.

Dressed in white robes, pilgrims piled into and on top of buses on their way to a ritual of prayer and reflection in Mina, 3 miles east of Mecca.

The journey caused massive traffic jams on roads to Mina, where pilgrims will spend the night in white, fireproof tents. Some pilgrims chose to walk the route.

The hajj, packed with symbolism and ritual, is one of the five pillars of Islam. Every able-bodied Muslim who can financially afford to must perform it at least once in his or her lifetime.