The French colonialists dubbed Vietnam's Muong Hoa Valley area the "Tonkinese Alps" and walking in these mountains is hard work.
Clinging to a clump of grass with one hand and a thin bamboo strand with the other, I feel myself sliding down the hill.
My feet slip down the steep path and my rump hits the ground hard, leaving a big muddy patch on my white shorts.
Finally I've stumbled, after three days of trekking through the wild Muong Hoa Valley near Sapa, in northwest Vietnam.
I've sloshed through rice paddies, scrambled up thin dirt tracks in bamboo forests and hopped over rocks in shallow mountain streams for almost 13 kilometres.
But in one moment of hesitation, so close to the end of the trail, I've ended my personal quest to remain upright.
Our whole group erupts in laughter, but after laughing so hard at all those who've fallen before me it's only fair.
The Muong Hoa Valley is criss-crossed by myriads of tiny bamboo aquaducts and mud channels which feed into planted terrace plots - mostly rice and some corn.
The plots are occasionally broken by small fenced ponds full of ducks and geese or even fish.
There are buffalo, pigs and cows kept in shady pens and chickens pecking around in the fields and paddies.
The local hill tribes - the Hmong, Dzao, Tay, Giay, Muong, Tai, Hoa, Xa Pho - have turned these heights into an agricultural powerhouse.
There's no shortage of water here, the sounds and sights of it flowing are always nearby.
And it's hot, incredibly hot - any breeze is a blessing during a trek.
Sure-footed Hmong women constantly trail you, waiting for any slip or stumble, ready to reach out with a helping hand when you do.
These women will be with you all day, walking many kilometres and asking "your country? your age?" and "your name?"
These questions turn into a friendship, but it can be costly.
At the end of the day they open woven grass backpacks and expect you to buy whatever knickknacks they have inside.
So you become fiercely independent, prepared to fall, eager to avoid any unexpected shopping.
But in the end you soften, realising that with hundreds of tourists walking through their homes and paddocks every day, it's only fair these women are allowed to make a buck or two out of us.
Our guide, a chirpy Hmong woman named Chai, leads us to a local homestay for the night.
We'd been expecting dirt floors, mosquito nets and painful broken english conversations, but we're surprised by a modern looking wooden house with showers, cold beers, power sockets to charge our smartphones and even Wi-Fi internet.
The beds are set around a central living room on two levels, there are wooden framed beds downstairs and simple mattresses upstairs.
As the sun sets over the peaks above and a calm spreads over the valley, we take in the scenery and rest our weary legs.
We help our hosts making spring rolls packed with wild mushrooms, but apart from that all we can do is sit, watch and wait.
Dinner is a smorgasbord of stir-fried pork, beef, tofu, crisp fried spring rolls and steamed rice followed by a pungent and biting shot of rice wine.
Afterwards, we mill about in the courtyard wondering what to do, while our homestay family watch Vietnamese sitcoms loudly in the kitchen.
There's a certain peace or meditation in trekking through the Muong Hoa Valley, which sadly feels as if it's on the cusp of being overrun by tourist hordes.
So before things change, it's probably time to go and see the place - endless rice terraces cascading downhill, a hard sun, the gentle trickle of water, wind rustling bamboo stalks - one step at a time.
Firmly treading, occasionally squelching and that dreadful sliding sound that only ends in mud and laughter.
SEVEN TIPS FOR SURVIVING A HIKE THROUGH VIETNAM'S MUONG HOA VALLEY
* Bring enough water to last you at least a day, two 1.25L bottles
* Wear thick, waterproof hiking boots or a pair of old shoes, as there will be mud, lots of mud
* Slather yourself with plenty of strong sunscreen, wait half an hour, then put on strong insect repellent, then wait at least an hour to give it all time to dry before setting off
* A raincoat or poncho is essential
* Walk at a slow, steady pace and find a place to rest in the shade
* Bend the knees and walk quickly in steep up or downhill sections of the track, it gives you a lower centre of gravity and makes it a shorter fall if you do
* Don't forget to take in the surrounding scenery, it's a truly majestic part of the world.
IF YOU GO
GETTING THERE: The Muong Hoa Valley is about 380km northwest of Hanoi. The most popular route is the bumpy overnight train to Lao Cai and then a bus up to Sapa, which is about 38km away. A local guide will walk you into the valley, about 8km from Sapa.
STAYING THERE: For accommodation, local homestays offer lodging and food at the cheapest rates, while also helping out local tribal people. Most have toilets, showers and some have Wi-Fi internet too. A local guide can organise homestays.