Bac Sum Pass, Quan Ba, Ha Giang

Region: Quan Ba
Best time: Early morning on clear days for the best chance of a cloud sea below the road. Winter mornings are coldest but often most dramatic.
Getting there: On the main road north from Ha Giang town towards Quan Ba — the first major climb of the Loop.

Bac Sum is where the Loop begins to feel real. You leave Ha Giang town on a flat road through the river valley, and then the road starts to climb. For the next 10 km or so, it winds up the mountainside in a long series of bends, gaining altitude steadily, and somewhere on the way up the lowland Vietnam you know falls away behind you.

On many mornings, the top of the pass sits above a sea of cloud. You ride up through forest, the air gets cooler, and then you break through into clear sky with a white carpet stretching back over the valley you just left. It does not happen every day — the clouds need the right temperature and humidity — but when it does, it is worth stopping for.

Bac Sum is not a dramatic single hairpin or a cliff-edge drop like Ma Pi Leng. It is a long, steady climb, the kind of pass that makes you feel the landscape changing around you. The forest thins, the rock changes colour, the air smells different. By the time you reach the top you are in a different world — the karst highlands of the Dong Van plateau.

One thing to know: this is a main road. Trucks, buses and local traffic use it constantly, and they do not slow down for tourists stopping in the middle of a bend. The road is good but winding, with limited visibility on many turns. Pull in only where there is space off the road, never on a bend. Don't ride it in thick fog or after dark — the combination of trucks, sharp curves and poor lighting is genuinely dangerous.

After the pass, the road drops into the Quan Ba area and soon reaches the Heaven Gate viewpoint, which is where most people take their first real photo of the trip. Bac Sum itself has no marked viewpoint, but a few spots on the upper section have enough shoulder to pull over safely and look back at the valley.

In winter (November to March), the pass is colder than Ha Giang town — sometimes by 10°C or more. Carry a warm layer even if town felt mild. And in the rainy season, water runs across the road in places; take the bends slowly and watch for gravel washed onto the surface.

Local tips

Carry a warm layer even if Ha Giang town felt mild — the pass can be 10°C colder.
Pull off only where there is room; never stop on a bend.
Early mornings sometimes bring a sea of cloud below the pass.