ASSISI, Italy (RNS) When some 550 religious and humanitarian leaders gathered in this Umbrian hill town last month to promote the causes of love and forgiveness, it was a spectacular reminder of the powerful charisma that this place holds for people of all faiths and none.

An estimated 6 million visitors came to Assisi last year, according to a spokesman for the convent of the Basilica of San Francesco. Some came, no doubt, to see the basilica's fresco paintings by the 13th- and 14th-century masters Cimabue, Giotto and Simone Martini. But for most, the biggest draw was surely the legacy of Francis himself, whose feast day is Thursday (Oct. 4).

A rich man's son who embraced poverty, celebrated the beauty and goodness of animals and nature, and sought to end conflict between Christendom and Islam, the medieval saint remains a figure of unmistakable relevance to many of today's most pressing social concerns.

Visiting Assisi, "you can see the world in which St. Francis lived, and you realize that we are not so different," said Charles Collins, a Texan living in Rome, who has organized several Catholic retreats in the town. "The world (Francis) spoke to is our world."

Assisi has been the site of two landmark interfaith summits -- in 1986, hosted by the late Pope John Paul II, and a more subdued 25th anniversary celebration, in 2011, hosted by Pope Benedict XVI.

Devotees flock to the Basilica of San Francesco to pray at the saint's tomb; but the nearby church of Santa Chiara, the burial place of Francis' friend St. Claire, is usually less crowded and thus "more conducive to contemplation," Collins said.

The American's favorite church in Assisi is the small one of San Damiano, where Francis first heard the voice of Christ calling him to service. "It is halfway up the hill, which allows you to walk, making a real pilgrimage," Collins said.

Not all pilgrimages to Assisi are Catholic, or even religious in any traditional sense. In recent years, a number of organizations have held retreats here focusing on the sort of eclectic forms of spirituality often categorized under the label of New Age.

"We found the energy in this place to be absolutely amazing in the purity of spiritual vibration," says the website of the Shared Heart Foundation, based in Santa Cruz County, Calif., which will soon hold its third retreat in Assisi.

Peggy Husch Rothschild, of Newton Centre, Mass., joined a Shared Heart group for a week last October, staying in rented rooms at a convent close by the Basilica of San Francesco.

"In small group discussion and in large group meditation, in song, and sometimes in dance, we opened up to places within ourselves that had been closed, sometimes for many years," said Rothschild, who is Jewish.

Her group also visited sites important in the life of St. Francis, including the cave which he used as a hermitage, and the tiny chapel of the Porziuncola (now encased in the Basilica of Santa Maria degli Angeli), where he founded the Franciscan movement.

Assisi also draws visitors with purely secular interests, of course. The rolling Umbrian countryside is ideal for hiking, and a 25-mile "path of peace" recreates Francis' trips from Assisi to the town of Gubbio, where legend has it that he pacified a wolf that had been terrorizing the locals.

Like most places in Italy, Assisi offers excellent cuisine, including several local specialties featuring truffles. Recommended restaurants include the Trattoria Pallotta and the more formal Ristorante San Francesco Assisi, whose dining room features a panoramic view of the basilica and the square in front.

About 85 percent of visitors to Assisi are day-trippers (Rome and Florence are both about two and a half hours away by train), so the town falls quiet at night, providing an opportunity for more intimate acquaintance with its steep, narrow medieval streets.

Eighteen convents offer rooms for visitors, with a minimum of two-night stay, at generally modest prices, though often with the limitation of a curfew (detailed information is available at www.sanfrancescopatronoditalia.it). A more luxurious taste of monastic life is available at the Nun Assisi Relais and Spa (www.nunassisi.com), a five-star establishment inside a converted 13th-century convent.

Such upscale digs might seem scandalously incongruous with the Franciscan ideal of holy poverty. For at least one believer, however, there is something providential even in the town's worldly attractions.

"I have some friends who complain about the army of irreligious tourists who now clog the city," Collins said. "But I am happy that the city's beauty, history, and inherent religiosity have the opportunity to touch them, to give them a small taste of the divine."