AFTER US President Barack Obama visited the Great Wall in Beijing on his first Asian tour, he told everybody: "It reminds you of the sweep of history and that our time here on Earth is not that long, so we better make the best of it."

Last month Obama became the fifth US president to leave his footprints on one of the world's man-made wonders. Like those before him, he was awe-struck by the magnificent fortification and landscape.

The section of the Great Wall he visited is called Badaling, the part most visited by celebrities and tourists.

If you are a first-time visitor to Beijing, Badaling is the place to see to appreciate China's awesome achievement.

However, for many Chinese like me or expatriates who have visited this so-called "official" Great Wall scenic site, climbing a section of the unrestored "wild" Great Wall in the capital city's outskirts is a chance to explore more of the historical treasure.

It was breathtaking to view it in the colors of autumn on a sparkling clear and sapphire-blue day.

Thanks to the hospitality of a friendly couple in Beijing, I had an unforgettable adventure last month in Beijing's suburban Huairou District. There we ventured onto the steep Jiankou section of the Great Wall, also known as the Jiankou Great Wall.

It is one of the most dangerous parts that has fallen into disrepair. Climbers have to be careful not to slip, there's no marked path, and some narrow portions are right next to a sheer drop 100 meters down.

This part of the wall was built in the early Ming Dynasty (1368-1644) and connects two other sections of the wall. It's a very famous portion of the 600-kilometer-long "wild" Great Wall.

The Chinese name literally means "Arrow Nock" because the shape of the mountain is like an arrow, with the collapsed portion of the wall as its nock. The wall was built along steep mountains, making it not only a magnet for photographers but also a popular travel destination.

Attracted by its fame, my friends chose Jiankou to experience the "wild" Great Wall.

About two hours' drive from downtown Beijing, we arrived at Yanqi Town, a small township near Huairou District. We had a good night's sleep at a pleasant and tranquil villa (Bake Gongshe, a mountain resort) then started off to Jiankou the next morning.

Following our online research, we headed to Xizhazi Village on the north side of the wall, locally known as Hou Jiankou, to begin our expedition.

Driving on the zigzag road around the mountains, it took us about 40 minutes to reach the entrance to the village. Farmers have turned the area into an ecological park featuring modern organic agriculture.

Admission to the village is 15 yuan (US$2.20). It's ironic that the tickets are printed with a warning: "Don't climb on the wild Great Wall," while attendants at the village parking lot tell you exactly where to start climbing.

Hiking upward on a meandering footpath full of twists and turns, we went deep into the mountains and for a while it seemed like an ordinary but demanding hike, without a glimpse of the Great Wall.

After half an hour, I suddenly saw a section of gray stone wall when I looked up to check directions. Standing on top of the mountain against a clear blue sky, the Great Wall inspired everyone to keep on going. Though I was sweating I pushed my aching legs to reach the wall as quickly as possible.

After one and a half hours of struggle, we finally reached a platform where a panoramic view of the Jiankou Great Wall opened up. Built of large white rocks, the platform looks like a deteriorated bridge connecting the wall to an observation tower where sentinels scanned for enemy troops. It's on the lower reaches of the wall, so you can look up into the distance or gaze down the mountain, enjoying a magnificent view of wild nature.

Bordered by jagged cliffs and steep drop-offs, the prodigious wall extends far away to the horizon, making it hard to believe that it was all built by hand. A gentle breeze wafted through the forest of autumn colors and cooled my face.

On a beautiful fall day I felt that I experienced the true Great Wall and I couldn't help thinking of history. I imagined a sentry standing guard in a remote tower on the frontier, missing his parents back home.

After a little rest and photo-taking, we decided to head south on the dilapidated wall to visit the "Beijing Knot," a point at the summit where three sections of the Great Wall converge.

Our team soon broke up because of the precipitous topography that demands all your skill and courage. At one point, you have to walk right along the narrow, unstable edge of the wall -- right next to a sheer drop. A slight misstep or brush could send you tumbling down at any time.

Another young woman and I were totally freaked out and gave up, while my friends, the Beijing couple, bravely carried on.

They climbed over the most dangerous part and kept going upward. The rest of us returned to the starting point and headed northward to glimpse the "wild" Great Wall in a safer way.

The Jiankou Great Wall connects with the Mutianyu Great Wall 10 kilometers to the east and the Huanghuacheng Great Wall to the west. Though my chicken heart prevented me (perhaps wisely) from exploring more of the Jiankou section, I learned from my braver friends that there are several scenic spots along the way to the "Beijing Knot."

"The Eagle Flies Facing Upward," an observation tower to spot enemy troops, is a must-see. Since it was built on the highest peak of the Jiankou Great Wall, it was said that when an eagle flies there, it can only do so facing upward before reaching the top of the tower.

My friends struggled to reach the heights. They later told me that this daunting part is best left to serious and experienced rock climbers with proper equipment.

So if you're not an experienced climber, like me, it's wise to follow my safer itinerary when visiting Jiankou.

When you complete the adventure and take the same route back to the village, you can visit Zhao's House on a farm. First discovered by photographers, it's now a hostel and restaurant offering countryside home cooking and drinks. The owners are friendly and enthusiastic farmers who like to chat and even offer visitors their cell phone number in case of emergency during the climb.