Throngs choked every alleyway and sidewalk in the city while a sea of white swirled 'round and 'round a cubical black building at its center. The city's visitors came from every continent, and many will never return.

Amid the crowds of ecstatic worshippers were six Utahns who traveled halfway around the world to participate in the largest Islamic gathering on Earth.

Every year, about 2 million Muslims flock to Mecca, Islam's holiest city, for a pilgrimage called the hajj. The event takes place during the last month of the Islamic lunar calendar, this year landing between Dec. 26 and Jan. 2.

"It's a great experience," said Akram Shaaban, who went on the pilgrimage for the first time this December with his wife, Inji. "It's hard to imagine (it), but when you're done, you want to go again."

The Shaabans, who live in Salt Lake City, traveled to the holy city with two other Utah couples after several years of planning.

Every financially and physically able Muslim must participate in the pilgrimage, one of the five pillars of Islam, at least once in life. Usama Baioumy, leader of the Muslim mosque in Orem, told a story to illustrate the hajj's importance for Muslims.

A couple years ago, a National Geographic photographer offered a gift to one of his subjects, an impoverished Afghan women.

"He asked her, 'What do you want?"' said Baioumy as he retold the story. "He was expecting her to tell him, 'I want a house for my children' ... (but) the first thing that came to her mind was, 'I want to go on the hajj.' That is the exact feeling of all Muslims."

December's journey marked Baioumy's fourth experience on the hajj, but his wife, Eman, had never participated before.

"I need to go again," she said at their home in Lindon.

"The problem is, once you go, you want to go every year," Baioumy chimed in.

But the Saudi Arabian government won't allow visitors to return for the hajj more than once every five years. Without some restrictions on attendance levels, the crowd would be uncontrollable. In fact, some years have seen participants trampled in the huge, ever-moving masses of people.

"If someone tries to go against the traffic and (they) fall down, there's no way to stop it," Baioumy said.

Larger crowds than usual crammed into the city this year, creating traffic jams that made the I-15 rush-hour commute look easy. During one particularly snarled section of pavement, the couples waited 14 hours to travel a measly 6 miles.

"There are always glitches, but you tend to forget about them because it's such a powerful experience," said Fuad Shihab, a Salt Lake City resident originally from Lebanon.