Ancient holy men did a lot of walking. From the early missionary St Paul, who spread the word of Christianity through the Mediterranean landscapes of modern-day Syria, Greece, Turkey and Italy [Images], to the fifth-century St Patrick, who ascended a mountain in Western Ireland to fast and pray, the saints and prophets of the world's major religions frequently traveled on foot to seek both fellowship and solitude.

Today, travelers can retrace the footsteps of their spiritual forebears and sign up for itineraries with names like "Footsteps of the Apostle Paul." And though some walking may be involved, 21st-century pilgrims are more likely to take advantage of amenities that their ascetic ancestors never dreamed of: last August, for example, the headquarters of the Catholic Church started its own charter airline service, Vatican Airlines. Its maiden voyage traveled from Rome to Lourdes, the famous French village where, in 1858, a teenage girl is alleged to have seen visions of the Virgin Mary, and where legions of visitors have since flocked in search of the purported healing powers of the village spring.

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The flight to Lourdes was an auspicious foray into religious tourism for the Holy See. The Vatican says its chartered Boeing 737 now plans to fly some 150,000 Catholic pilgrims to different holy sites throughout the Middle East and Europe -- "with fares 10 percent lower than the competition." According to the airline, future destinations "could include Fatima in Portugal and Santiago di Compostela in Spain, the Holy Land, Poland and a Catholic shrine in Mexico."

The number of faithful flocking to shrines, mosques, synagogues and temples -- or touring the significant sites in the history of their particular religion's development (or its leaders' lives) -- appears to be multiplying like loaves and fishes. Religious travel is "one of the fastest-growing segments of worldwide tourism," says Kevin Wright, founder of World Religious Travel Association and author of the book The Christian Traveler Planner. "According to the WTO (World Trade Organization), it's valued at $18 billion, with 300 million travelers and 600 million trips each year," he says. Christian tours account for approximately 90 percent of the North American religious-travel market, according to Wright, with the remaining 10 percent roughly split between Jewish and Muslim tourists.

There is also a contingent of travelers, Wright says, who aren't necessarily religious, but follow religion-centered tours out of "historical and cultural interest." This group comprises a small portion of the total market, he says, but "there are trends of it growing."

Aside from its sheer growth, Wright says there have been several noticeable changes in the religious-travel industry in recent years. The demographic has shifted to younger travelers, and there has been a noticeable move toward "fellowship" tours, religious groups traveling together (on faith-focused cruises, for example) which are less about a particular destination than cultivating spirituality with like-minded travelers. In addition, says Wright, religious tourists have shifted from "a budget mentality to a demand for first-class products and services."

This luxury emphasis represents a marked break from the past, says Dallen Timothy, professor in the department of geography at Brigham Young University and author of Tourism, Religion and Spiritual Journeys. "The word 'travel' comes from the ancient word 'travail,' which means hardship. In medieval periods, travel was meant to be difficult. It denoted sacrifice and humility," he says.

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In the last 50 years or so, explains Timothy, religious travel has "become much more commodified," and pilgrimages "have become a major commercial endeavor. Every religion does it."

A typical 10-day tour of Bible-related sites in the Middle East may run from $1,800 to $3,000, depending on the level of accommodation, season, and whether or not airfare is included. 206 Tours, a New York-based operator that specializes in pilgrimages and spiritual journeys, offers a 10-day "Holy Land" package to Israel that includes "first class" hotel accommodations, daily breakfast and dinner, and an accompanying "spiritual director." A trip departing in May, which includes roundtrip airfare from New York, lists for $2,849.

In the non-Christian world, pilgrimages and religious tours also have evolved from travail to luxury travel. According to the UK's Channel 4, while "(Haj) pilgrims of old slept in basic tents with minimal provisions, now they have the choice of luxury tents� equipped with televisions, Internet, computers, refrigerators, electric lighting and mobile phones." The British agency Afta Tours, specializing in luxury pilgrimage for Muslims, offers a "Super Deluxe" 17-day Haj package for 5,950 euros (about $9,000 dollars) per person, that includes accommodations in luxury hotels, guided Islamic tours and lectures, and private camps near the Sacred Mosque itself.

A Jewish heritage tour offered by the Atlas Travel Network combines visits to significant religious sites in Eastern Europe with plenty of opportunity to relax. The itinerary for day five of the twelve-day trip combines a visit to Krakow's ancient "Remuh Synagogue where Jews still worship today, and the nearby cemetery" with a stop at "the Market Square, with its Renaissance-style Cloth Hall; its arcades lead to numerous shops -- you can shop to your heart's content!"

Kevin Wright says the volatile political situation in the Middle East can present challenges for religious-themed tour operations. "The perception of violence is always the number one challenge for tour operators and travel providers selling trips to the Holy Land," he explains. "However, any violence that takes place in the Middle East is typically far removed from the traditional tourist sites. Hence, the biggest challenge for travel companies selling the Holy Land is overcoming the misperceptions of violence in tourist areas."

Lately, that perception hasn't slowed visitation to Israel and Jordan -- both countries had record numbers of visitors last year. Israel hosted more than half a million Americans in 2007, an all-time high, (according to the country's tourism commissioner), and Jordan's Tourism Board said the country's tourism revenues increased by more than 13 percent in 2007.

As they have for millennia, the world's holy sites continue to exert a powerful draw over the faithful and the curious. These days, with modern transportation and updated standards of travel, it's getting easier to walk in the footsteps of the holy ones, with much less of that ancient travail.

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