The small, elderly Chinese ladies walking with us have the strongest calf muscles I've ever seen.
Fern, who is wearing a pair of new Nikes that don't quite fit the rest of her look, tells me in broken English she's 66 and has hiked the Great Wall of China every day for the past 10 years selling souvenirs to support her son and grandson.
It's a hot, sunny day. There's a small, cool breeze, but it's not enough to beat the heat, and I gulp water every time I stop to take a picture - which is about every 10 minutes because I can't get over the sheer expanse of the World Wonder.
Fern is unfazed. Chuckling at my breathlessness, she offers me her shoulder to lean on as we clamber down some of the particularly steep steps. A good saleswoman, she pulls a fan with a picture of the Great Wall out of her bag. I don't particularly want it, or the set of chopsticks I also buy, but it seems like a fitting memento of the journey and characters on the wall, like Fern, who add colour to the centuries-old man-made feature.
Built between 221BC and 206BC at the order of Emperor Qin Shi Huang of the Qin Dynasty, the wall twists and turns for more than 21,000km from Lop Lake in the west to Dandong in the east. While it can't - despite common belief - be seen from space, it is by far the longest man-made structure in the world.
Our 7km hike isn't taking place on the section of the wall closest to Beijing that many tourists opt for, but on the Jinshanling, about a three-hour drive north of Beijing.
We arrive the night before and stay in the nearby town of Gubeikou so we can see the wall at sunset. Our enthusiastic guide, Ray, marches us up the 1000 steps to the wall lugging a chilly bin of champagne and telling us just how fast he can complete parts of the wall.
The top is nothing short of incredible. Images online, photos friends have taken, a documentary I once watched, are nothing compared with being there. We toast to the night and take numerous photos, from group shots to the "casual lean" and "staring into the distance looking pensive". Being blond, I also find myself being beckoned into a couple of Chinese tourists' shots.
Nestled in steep, green bush, some of Jinshanling is well-maintained while other older parts are crumbling. Fern points to markings on some of the stones and explains they're the signatures of the soldiers who carried them up the steep hillside thousands of years ago.
Coming from a country as young as New Zealand it's amazing seeing such history first-hand. I think too of the men who died building the wall - historical records vary but the death toll is thought to be in the hundreds of thousands.
All the way along the wall there are towers, and in every tower there is at least one elderly Chinese man selling drinks and souvenirs. Most of them speak less English than Fern and are more weathered, teeth missing here and there, skin roughened from years under the hot sun.
There are few people hiking the wall, or ducking their heads in and out of the towers. We have perfectly timed the hike around the Dragon Boat Festival to be away from the crowds.
Some of my group take the gondola to the bottom, but I walk. I may not have calf muscles to challenge Fern's but I'm jubilant and reward myself with a refreshing mango iceblock from a seller at the bottom of the wall.
Cathay Pacific and Cathay Dragon offer daily connections to Beijing via Hong Kong from $969 return in Economy Class.
Wendy Wu's 27-day Grand Tour of China starts from $7480 pp, twin share.