Fourteenth-century bricks wobble under my feet and ancient pebbles skitter down behind me. When Ming dynasty soldiers went up this steep incline, they would have been hoisting themselves up with a horsehair rope; I have to scrabble with my hands, grabbing onto stones and tree roots. If I had wanted to tumble to my death, I reflect, it would have been much more convenient to do it out of a window at home, rather than traveling halfway around the world to hike on the Great Wall of China.

Right now, I’m climbing the Wall more than I’m hiking it. I’m clinging to a ten-foot-wide ribbon of stone, just a few degrees shy of vertical, with about two hundred feet below me and another hundred feet left above me. My legs are starting to cramp and sweat is trickling into the small of my back, but there’s no good place for a rest.

I need to plan every single step. If I put my weight on a pile of stones that’s just slightly less stable than some of the other piles of stones, my descent will be much faster and more painful than my ascent has been. I discover that the best handholds are loopholes: the ancient arrow slits that punctuate the battlement on either side. The part of my brain not concerned with staying alive dimly registers the notion that this Wall was built not as a monument, but as a war machine.

At last, I pull myself onto a plateau, where an old guard tower stands. Sprouting from the stones are two lonely windblown trees. I’m hiking with William Lindesay, a British-born expert on the Wall, and Vivi Vejen, a young Danish secretary. Lindesay, lanky and white-haired at age 48, looks a lot like Jim Jarmusch. We are standing in Hebei Province. Beijing is only a few hours away–but at an altitude of 3,600 feet, civilization feels much more distant than that. I can make out some dirt roads and some farmhouses below–otherwise, it’s all rolling hills covered with the rusty burrs that are leafless trees. Looming in the distance, I can see the Yan Shan mountains.

The one constant: the Great Wall, bobbing and weaving its way through the hills, stretching out for mile after mile, all the way to the horizon. What we see in this valley is mind-boggling–but the Wall goes on for over a thousand miles after that. We stand, panting and gazing, marveling at this immense stone structure, seemingly laid over the landscape as casually as a piece of string.

“Up here,” Lindesay says, “you realize that calling it ‘Great’ is actually a humorous understatement.”

Before seeing the Great Wall, I thought of it as a historic sidewalk: a colorful and easy way to stroll from one end of China to the other, if you had enough time. I was wrong.

To start off: the Great Wall isn’t just one long wall. “Great Wall” refers to all the defensive fortifications built in northern China over two thousand years to defend the Middle Kingdom from Mongol invaders on horseback. In some regions, there were multiple walls, a whole system blocking every pass, which is why nobody knows exactly how long the whole network is. But if you measure from its start in the Gobi Desert to its end at the Yellow Sea, that’s about 1,500 miles, or roughly the distance from Baltimore to Denver.

Much of the Great Wall has been abandoned since the fall of the Ming Dynasty in 1644 (it wasn’t as effective at repelling the Mongols as the Chinese had hoped). Certain sections of Wall have been reconstructed for visitors–some even feature cable cars and a waterslide park. But outside of those tourist traps, the Wall has been abandoned for almost 400 years–and the wilderness has been taking back its own.

“Two weeks ago, this was an archway,” Lindesay says. What’s in front of us now is, well, a big pile of rocks. Guard towers dot the Wall every hundred yards or so; many of them are in some state of collapse, as time and seismic activity have taken their toll. Thorny brush and small trees have found purchase on top of the Wall–as we walk along, I feel like I’m walking through a paved forest, with a battlement on each side. “They like to say that the Wall’s wide enough for two teams of horses,” Lindesay notes as we pick a path through the undergrowth. “What they don’t like to say is that nobody ever rode horses up here–mules don’t even like to come up here.”

Then the view opens up on my left. The battlement there fell apart at some point–decades ago? centuries ago?–and the only things stopping me from plummeting thirty feet onto the rocks below are the treads on my boots and the structural integrity of some loose bricks.

The hike is a first-hand lesson on the art of war. The Great Wall seems to rise and fall with every peak and crest–because the Chinese wanted to hold the high ground for defensive purposes. I learn how to tell the difference between a buttress and an armory: the buttress sticks out of the Wall on the Mongolian side, and has lots of loopholes for arrows.

Every hundred yards or so, we come to another guard tower, which sets up a steady rhythm of archaeological discovery. Some are so ruined that people have made piles of their stones, providing an unsteady stepladder to the roof. At another, Lindesay and I scrabble in the dirt, revealing a centuries-old roof tile, which he then reburies. Every single time I enter a guard tower, I expect it to collapse around my ears, forcing me to bolt through the doorway, just a few seconds ahead of certain doom. I find that I’m gently humming the Indiana Jones theme to myself.

We come to another guard tower, this one daubed with Chinese characters in red paint. “Those idiots!” Lindesay explodes. “They’ve written ‘Beware of fire.’ Despair, despair. Can you imagine anyone in the United States writing on something five hundred years old?”

“We don’t really have anything five hundred years old,” I say.

“Exactly.” Lindesay takes a picture of the paint, hoping to dissuade the local fire wardens from doing it again. Although Lindesay is also fighting a constant war against littering, the Great Wall has suffered surprisingly little damage at human hands, because it has very few decorative fripperies to steal. What have gone missing are various historical stone tablets, indicating who built or commissioned a particular section of the Wall. “They’re usually taken by farmers,” Lindesay says. “I’ve seen some as doorsteps, or parts of pigsties. I’ve even seen a woman washing her husband’s undies on a tablet with the emperor’s name on it.” He chuckles. “Power to the people!”

We hike the Wall for eight hours before retreating to the valley; in all that time, we see only one other group of people (an overwhelmed family of Japanese tourists, stumbling along in sandals). On the Wall, I don’t feel like I’m in any particular country: the land I’ve traveled to is a much stranger one, called the past. As we descend into the valley, we fast-forward through recent Chinese history.

Some of the hillsides have been leveled into tiers; from a distance, they look like ruffled potato chips, but closer up, they’re abandoned fields. This is a byproduct of the Cultural Revolution, Lindesay says. Between 1968 and 1976, Mao Tse-Tung forced huge numbers of urban Chinese intellectuals to relocate to the countryside to discover the joys of the peasant agricultural life. This huge influx of manpower had to be given something to do, so suboptimal areas like hills were adapted into fields. After Mao’s death three decades ago, they went fallow. As we step onto a dirt road, I see an empty soda can with “Coca-Cola” in Mandarin characters: welcome to China in the 21st century, the burgeoning global market.

Lindesay leads us to his farmhouse, a small red building where we will spend the night: the frozen pipes mean no showers, but beds and hot water bottles seem the very definition of decadence. His family’s cook has come up from Beijing and produced a feast. We eat dinner sitting on top of a clay furnace, with a dozen dishes for the three of us, including trout, a mountain of onion pancakes, spicy chicken, soup, and “tiger salad.” Around his second beer, Lindesay tells us how he ended up in China, thousands of miles from home.

Growing up in England, he had been fascinated by the Great Wall, but had forgotten about it until he and a brother ran the length of Hadrian’s Wall (an ancient Roman fortification in Britain, 73 miles long). He decided that the next step was to run the Great Wall. And so, in 1986, with only a small backpack, some bad maps, and a few words of Mandarin, he began his epic journey, starting at the eastern end, in Shanghaiguan.

On his second day, lost and running out of water, he “staggered back.”

The next time, Lindesay started in Jiayuguan, the western end: he made it 125 miles before he ran into the law. He had been running through “closed” areas of China, where foreigners are not allowed to visit. They sent him back to Beijing. “I also got dysentery and a broken toe,” Lindesay says ruefully.

The following year, he tried again. He kept running east, following a Wall that in some locations was only a gentle hump in the ground. When he found shelter, he would often attract dozens of gawkers curious to see a white man. That sometimes also meant a visit from the Gong An Ju police. They often expressed admiration for his journey, but would unfailingly arrest and interrogate him.

Lindesay was arrested nine times on his journey–but deported only once. Usually he could pay a fine and promise to return to Beijing. Then he would bolt for the next province. Once, he even gave the police the slip in a sandstorm. Along the way, Lindesay met his future wife, Wu Qi, and found that the Wall wouldn’t let go of him. He wrote a book about his epic jog (Alone on the Great Wall), founded the conservation group International Friends of the Great Wall, and kept exploring the vast monument. If you’re going to get obsessed with one thing, it’s good to choose a big thing.

The next morning, we wake up at 4:30 am for a frog-march up to the Wall to see the sun rise. I start with four layers of clothes for the freezing night air, but find myself sweating so prodigiously that I have soon stripped down to a single shirt. I stumble over countless patches of ice in the dark, finally reaching the top, wheezing and spent.

The dawn light casts a rosy veil over the wall; the stones turn an unspeakably beautiful pink, as they have tens of thousands of times before. Lindesay points out the craftsmanship of the waterspouts and the mortar between the bricks; far behind him, there are farms and villages. On the horizon, larger towns twinkle.

Patrolling the Great Wall five hundred years ago, I imagine that soldiers must have felt like they were on the dividing line of the world: on your left hand, barbarians, on your right, civilization. This is not quite accurate–the Chinese lived on both sides of the Wall, and it was intended as a final line of defense–but I still feel like I’m balancing on the edge, only now it’s the modern world in my head and the history crumbling under my feet.

After two days of vigorous hiking, I haven’t covered even one percent of the Wall’s length. I’m briefly disappointed, but then I remember that traversing the Wall is a quest that can eat up years of your life–which of course, pales against the centuries of labor that went into building it. It’s good to be awed by sheer size and to remember that men can build mountains of their own.

Article by Gavin Edwards. Previously unpublished (commissioned by Men’s Journal, circa 2005).