At the onset of the coronavirus pandemic, with travel restrictions in place worldwide, we launched a new series — The World Through a Lens — in which photojournalists help transport you, virtually, to some of our planet’s most beautiful and intriguing places. This week, Andrea DiCenzo shares a collection of images from central Iraq, taken in 2019.The walls of the Imam Abbas shrine in Iraq’s holy city of Karbala seemed to heave and sway with the boisterous, devoted crowd. By holding onto a rope, ushers partitioned a makeshift runway from one entrance of the mosque to another. This was the stage where a parade of religious men and women would perform latom, or ritual chest-beating, and other forms of ceremonial mourning.The first group was understated: Dressed in black outfits that were deliberately muddied and torn, the group of Iraqi pilgrims beat their chests in unison. They cried out in grief — “Oh, Hussein!” they shouted, in reference to a 7th-century Islamic leader — so loudly that they cut through the music blaring from the speakers dragged behind them. The next group was younger and rowdier. In an explosion of chaotic energy, these young devotees struck at themselves and at each other with abandon.This wasn’t a normal day at the Imam Abbas shrine. This was Arbaeen, and the shrine would see some 15 million visitors and thousands of religious performances pass through its red glow before the two-day event concluded.Every year, millions of pilgrims descend on the central Iraqi city of Karbala, a usually quiet desert city, to commemorate the religious holiday of Arbaeen, one of the largest organized gatherings of people in the world. The events center on two adjacent mosques: the Imam Hussein and Imam Abbas shrines.The event is a spectacular display of grief, mourning and religious ecstasy. It commemorates the death of one of Shiite Islam’s most important leaders, Imam Hussein, a grandson of the Prophet Muhammad. Hussein is said to have died 1340 years ago in the dusty plains of Karbala. A grave was established to commemorate his death, and the city of Karbala, in what is now modern-day Iraq, slowly built around it over time.In 2019, when a colleague told me the Imam Abbas shrine was inviting a small group of journalists to visit during Arbaeen, I jumped at the chance to go. The shrine was instrumental in organizing my stay in Karbala; they arranged my tourist visa and helped me negotiate travel both within Iraq and among the massive crowds in Karbala. (I paid my own travel expenses but was given a room at a modest hotel owned by the Imam Abbas shrine.)My only moment of uncertainty came shortly before heading inside the Imam Abbas shrine. A group of clerics at the shrine queried whether it would be appropriate for me, a woman, to rove around and take photographs. After deliberating for 15 minutes, they permitted me to enter. It was hard to tell if I had fallen on the winning side of a religious debate, or if the rightly famous Iraqi sense of hospitality had simply won out.Tradition holds that, in A.D. 680, Hussein and his followers were on their way to challenge the succession of Caliph Yazid, whom they saw as an illegitimate successor after the death of Prophet Muhammad, the founder of Islam. Yazid responded by sending a massive army to intercept Hussein, who continued to refuse allegiances with the Caliph. A battle ensued, and Hussein and all his followers were massacred. To this day, Hussein’s death is a defining drama of the Shiite faith and, in Christ-like fashion, remains powerfully resonant.Nowhere is this more visible than in Karbala during Arbaeen.Every year after the U.S. invasion of Iraq in 2003 — until 2020 — millions of pilgrims have traveled to Karbala, 60 miles southwest of the capital Baghdad. In the years of relative calm since 2010, the city of Karbala, together with its sister holy city of Najaf, the seat of Iraq’s pre-eminent Shiite clerical establishment, have become major centers of economic power and theological influence. This was unthinkable under the dictatorship of Saddam Hussein, when Shiite religious events were banned, and clerics were hounded from Iraq.Last year saw the shrines at their peak. Once inside, pilgrims offered a religious and cultural demonstration to express their love for Imam Hussein, often through choreographed chanting and flag twirling, but sometimes through violent (and less choreographed) flagellation, like the intense display I witnessed on the first day. In either case, nearly everyone was in tears, grieving. An astonishing number of people passed out from the emotional intensity of the experience.Many of the pilgrims within Iraq and from neighboring Iran make the journey by foot, trekking and camping for hundreds of miles along routes lined with stalls that dispense hot meals and encouragement. In recent years, Iraqis and Iranians have been joined by hundreds of thousands of religious tourists from a growing number of countries outside the Middle East, including the United Kingdom, Bosnia, Pakistan, Malaysia and Australia.Most foreigners come as groups organized by Iraqi travel agencies specializing in pilgrim tours. Individual visas are by invitation from one of the city’s two shrines. But, in comparison to Hajj, a similarly significant pilgrimage in Mecca, Saudi Arabia, what makes Arbaeen unique is the fact that the shrines actively invite leaders and people of other faiths.Of course, this year has proved to be anything but ordinary. Iraq’s religious tourism industry — which, until 2020, was the country’s largest non-oil economic sector — has been decimated. And for Arbaeen, which began on Oct. 7 and ended on Oct. 8, the government issued only a few thousand religious tourism visas. Clerical and health authorities are worried that continuing rites at the holy cities might become super-spreader events.This year, as a result, Arbaeen was once again mostly for Iraqis.Andrea DiCenzo is an American photojournalist whose work focuses on armed conflict and humanitarian crises throughout the Middle East. You can follow her work on Instagram.