Tens of thousands of Muslim pilgrims have spent the day in prayer there at the holiest site in Islam.
Up to two million Muslim pilgrims are converging on the Saudi city of Mecca for the annual pilgrimage, known as the Hajj.
The Saudi authorities say a record number - 1.5 million - have come from outside the country, with many rushing to beat Wednesday night's deadline to arrive in Saudi Arabia.
The five-day ritual begins in earnest on Saturday.
Making the Hajj at least once in a lifetime is the sacred duty of every able bodied Muslim who can afford it - but as air travel has become easier, numbers have swollen.
Holiest site
A moving tide of people has been converging on the Grand Mosque in Mecca.
Tens of thousands of Muslim pilgrims have spent the day in prayer there at the holiest site in Islam.
They have been circling the large, cube-shaped structure known as the Ka'aba and praying for everything from forgiveness to victory over those they see as the enemies of Islam.
Numbers restricted
This year, the Saudis say, a record number of pilgrims are expected to reach Saudi Arabia from overseas.
Two years ago, the authorities limited their own citizens to making the Hajj only once every five years in an effort to control numbers.
That followed a fatal stampede in 1998 when more than 100 pilgrims were crushed to death during a stoning ritual.
The year before, more than 300 lost their lives when a fire swept through a tented camp.
Safety precautions
Since then, the Saudis have spent hundreds of millions of dollars on safety precautions.
They have constructed tens of thousands of fireproof tents and introduced ways of staggering the flow of pilgrims through certain congested areas.
So far, their efforts have paid off as the Hajj has now been trouble-free for the last two years.
As this year's pilgrimage builds towards its climax on Sunday, those in charge will be keeping a close watch on the estimated two million pilgrims from a hundred countries.