Human beings evolved on the plains of Africa as hunter-gatherers, and despite settling into towns and cities, we are still best suited for life in our environment of evolutionary adaptation, not the zoo-like conditions we have built for ourselves. We are at our most human when we live outside, walking all day, never lingering in one place too long, sleeping in temporary locations. In contrast, human behavior in a city is remarkably similar to that of animals confined in a zoo. Desmond Morris explores this idea in his book, The Human Zoo.
All over the world, for centuries, people have walked great distances not for trade, education, food, or other material benefit but for inner reasons that—for want of a better term—are called spiritual. They are physical journeys toward a non-physical goal. Pilgrimages do not have the same features across all cultures, however. The Muslim pilgrimage to Mecca is very different from a medieval Christian pilgrimage, which shares some features in common with Buddhist pilgrimages. A thru-hike in America most resembles a medieval Christian pilgrimage.
For medieval Christians, travel to Jerusalem was too expense and too dangerous. Instead, the tomb of Saint James in Spain became the most popular pilgrimage destination for Western Europeans.
Pilgrims followed four main roads through France and over the Pyrenees mountains to unite at Puente La Reina, then hiked the "Way of Saint James" to the saint's shrine.
Like a thru-hike, this medieval pilgrimage had specific beginning and end points, as well as a designated route along a footpath with no express purpose except that as a pilgrim trail. This is in contrast to say, the Trans-America Bike Path, which is a route drawn across different linked roads also used for normal, day-to-day business. Pilgrims planned their journey by consulting guidebooks like the Liber Sancti Jacobi (or Book of Saint James). Similar to the tradition of trail names, medieval Christian pilgrims would adopt a “pilgrim name” during their journey, usually the name of a saint that inspired the pilgrimage. Businesses cropped up along the route to outfit pilgrims. Monasteries and abbeys provided food and shelter—the medieval equivalent of hostels. Upon reaching the end, pilgrims received a special metal coin as proof they had reached the end, similar to the thru-hiker’s patch.
Today the Way of Saint James (often shortened to "the Way") has become a backpacking destination. People still follow the pilgrim trail, but their motives are secular, rather than explicitly religious. While these hikers may not have great interest in the shrine or relics found at the end of the journey, the journey itself is no less personal, inward, and perhaps spiritual than when pilgrims walked it a thousand years ago.