Ha Giang is where Vietnam runs out of country. The city lies on the Lô River in the far north, just a short ride from the Chinese border, and it is the gateway to one of the most dramatic road circuits in Southeast Asia. Beyond the last streets, the road lifts into the Dong Van Karst Plateau, a UNESCO Global Geopark since 2010, where limestone peaks and gorges crowd every horizon and terraces of corn and rice climb the hillsides.
The loop is about three hundred and fifty kilometres, normally ridden over three or four days, and it deserves that time. The road climbs through Quản Bạ, where the hills are shaped like twin breasts, then Yên Minh and Đồng Văn, the old stone town where a market draws Hmong, Lô Lô and Tay people in traditional clothes on Sunday mornings. Near Sà Phìn is the palace of the Vương family, a Hmong clan that once ruled the region. The surface is tarmac for most of the way, but it is narrow and steep, with hairpins, blind bends and sudden gravel, and heavy fog can appear in minutes. Landslides are common in the wet season from May to September.
The great moment is the Mã Pí Lèng Pass, where the road is cut into a cliff high above the Nho Quế River, which runs in a green ribbon at the bottom of the Tu San canyon, among the deepest in Southeast Asia. The views are staggering, with layers of mountain fading into the distance, and the traffic, mainly local trucks and motorbikes, is slow. Autumn brings buckwheat flowers in pink and white on the plateau, usually in October and November, and the terraces glow gold in September.
Fuel is available in Ha Giang city and in every larger town on the loop, and small roadside stalls sell petrol in bottles in the villages. Homestays with simple meals, rice wine and a warm bed are the best way to sleep. Take warm clothes, since nights at altitude are cold, and rain gear all year. Check the weather before you go, and take it slowly, because the road does not forgive speed.