Ha Giang is the last real town before Vietnam runs out of road and turns into limestone, a small, busy provincial capital on the Lo river, about as far north as you can go without crossing into China. About thirty thousand people live here, in a grid of shops, cafes, homestays and motorbike rental places that exist because of the ride that begins at the edge of town. This is where riders sleep, sort out their kit and eat a big bowl of pho before the mountains, and it is a sensible base for exactly that purpose.
The Ha Giang Loop is the draw, a few days of tight, steep, foggy mountain road through the Dong Van Karst Plateau Geopark. The road climbs from the valley through the Heaven's Gate pass at Quan Ba, past terraced rice fields and villages of the Hmong, Dao and Tay people, to Yen Minh, Dong Van and the border country at Lung Cu, where a flag tower stands at Vietnam's northernmost point. The highlight is the Ma Pi Leng Pass, a narrow shelf cut into a cliff above the Nho Que river, which runs a startling jade green at the bottom of one of the deepest canyons in Southeast Asia. The tarmac is mostly decent but narrow, with sharp hairpins, sudden potholes, mist and the odd buffalo. Take it slowly, and avoid riding at night.
The pass was built by hand in the early 1960s. Thousands of volunteers, many of them young people from across northern Vietnam and from local minority communities, worked with picks and dynamite for years to carve the road from the rock, and it became a symbol of national effort. Near Sa Phin, a short ride off the main route, stands the old palace of a Hmong chieftain family, a house of stone and wood from the early twentieth century. Markets in the hill towns, on certain days of the week, are colourful gatherings where people trade in traditional dress, and the weekly Sunday market in Dong Van draws crowds.
The landscape is spectacular. Stone peaks rise from the fields like broken teeth, and terraces of rice, maize and buckwheat climb the slopes, with pink buckwheat flowers in October and November, and plum blossom in late winter. The air is cool, damp and smells of wood smoke, and the mist often hides everything until it suddenly lifts.
Fuel is easy to find in town, so fill up before leaving. Pack a rain jacket, warm layers and a phone with offline maps, and make sure your bike and brakes are in good order. Beds in town are cheap and simple, and an early night is wise.