Across the grassy esplanade before the great basilica built into the mountain by the grotto where it all started, a slow procession in blue and white silently makes its way.

This is the daily devotion of the enfeebled and the sick and the death-bound. They do not walk, they roll, most of them. They sit like aging monarchs in big blue armchairs on three wheels, identical chariots by the hundreds pushed or pulled by nuns in their nursing whites.

Thousands of other people, mostly elderly, watch silently as the procession moves down into an underground amphitheater for an afternoon service of prayer, song, and healing. Together they compose today's or any day's pilgrimage to Lourdes, site of one of the most beloved miracles in Christendom.

Once upon a time, 141 years ago, in this lovely southwestern French village in the foothills of the Pyrenees, a 14-year-old girl saw an apparition she took to be the Virgin Mary. Eighteen times over five months the impoverished, illiterate Bernadette Soubirous experienced this vision in white. She heard pronouncements, some mysterious, some concrete: build a church here, for example.

From that legend, and the eventual canonization of Bernadette as a saint, Lourdes has become the most popular Roman Catholic pilgrimage destination in the world, after St. Peter's Basilica in Rome. About 5 million people come here annually to wash in the sacred waters and worship in the imposing 19th-century basilica that dominates this sprawling old park of chapels, hospices, infirmaries, libraries and auditoriums.

Some are pilgrims, others simply tourists, but many if not most are here for one reason: healing. According to the shrine's annual estimates, nearly a million visitors are on organized pilgrimages, usually with the local Catholic parishes, often accompanied by nurses.

More than half come from France, but on a recent day the first 10 people stopped at random spoke neither French nor English. Most of them were from Italy, the second largest source of Lourdes pilgrims. But more and more North and South Americans and Asians are turning up.

The pilgrims tend to be of modest means, and either a longstanding faith or one seized in extremis. They tend to have a serious or terminal medical disability. According to a Lourdes official who refused to give his name, Lourdes medical facilities officially certify 85,000 cases of need a year.

They are hopeless cases, in one sense, except you could not call these people hopeless.

"I might be dead if I didn't keep coming here," said a smartly dressed elderly woman. "You'd understand if you were sitting where I am."

The town-owned organization that runs the shrine complex takes its curing reputation seriously. It has a long-established Medical Bureau that certifies cures according to exhaustive medical analysis.

The Lourdes Web site (www.lourdes-france.com) provides, among much else, a list of the 66 cured since 1858, and what they were cured of: The most celebrated recent case was that of Jean-Pierre Bely, who had multiple sclerosis and on a single day's visit on Oct. 9, 1987, fully regained all his normal functions. In February, the Medical Bureau said his case defied any medical explanation.

With such an interesting record of success, it is not hard to diagnose Lourdes' popularity. In a continent that has nearly ceased practicing its Catholic faith since the last world war, and where the late-century secular society is in full flower, Lourdes is one place where you can still feel the pulse of religiosity.

Cheap and easy travel has fed a hunger throughout the supposedly post-Christian world for religious pilgrimage, usually to shrines like this one associated with a miracle or a saint or both. (Bernadette, who died at 35, was canonized by Pope Pius XI in 1933.) Lourdes, 19th century in its inspiration and early 20th in its architecture, has emerged--perhaps accidentally, perhaps providentially--as a quietly modern kind of religious institution.

The 1958 auditorium where the armada of blue chairs ended its journey is an underground hangar that comfortably holds 15,000 and uses big-screen technology and sophisticated lighting and music--and six languages--to hold together the twice-a-day mass blessings.

"Even if they are not physically cured, they receive another kind of cure--psychological, spiritual. They live the experience of a reconciliation with God," said the Lourdes official.

They stand in line to touch the smoothed rock around the bubbling water in the grotto where Bernadette met her miracle. "Awesome," whispers an American teenager in the heavily European crowd. The spring of holy water can be seen, but not touched, and volunteers gently prod the visitors along.

This is where, on Feb. 11, 1858, Bernadette said she heard a noise like a gust of wind and then saw a girl with a blue sash around her waist, a yellow rose on each foot, and rosary beads on her arm. Thousands began to accompany her on return visits to the grotto, many of them without any sign of the Virgin Mary.

In one of the 18 apparitions that continued until July, Bernadette was told, "I do not promise to make you happy in this world but in the other." In another, "Go, tell the priests to bring people here in procession and have a chapel built here."

A subsequent analysis by the local Catholic diocese declared that it was the Virgin Mary who had spoken, and millions continue to believe this is a place where miracles can still happen.

CAPTION: Pilgrims kneel at Lourdes grotto. The Catholic shrine in France reportedly was the site of apparitions of the Virgin Mary in 1858.