Đồng Văn is the town at the top of the loop, a small market centre high on the karst plateau, close to the Chinese border, and the place most riders spend a night. It sits in a bowl surrounded by limestone peaks, and its heart is an old quarter of traditional houses with mud walls, wooden doors and tiled roofs, built around a market hall. The houses are a hundred years old or more, and in the evening the lanterns are lit, the cafes fill up and the air smells of woodsmoke and grilled meat.
Every Sunday, the market draws people from the villages for miles around: H'Mông, Lô Lô, Tày, Dao and others, many of them in traditional dress, who come to sell livestock, vegetables, textiles and tools, and to meet friends over bowls of thắng cố, a stew of horse meat and offal that is not for everyone, and glasses of corn wine. It is a colourful and noisy affair, and it starts early. The town has become popular with tourists in recent years, and the old quarter can be busy, but the market is still very much a local event.
The plateau around the town is part of the Đồng Văn Karst Plateau Global Geopark, recognised by UNESCO for its geology: vast expanses of grey limestone, sinkholes, caves and fossil beds, some of them hundreds of millions of years old. About fifteen kilometres west, in the village of Sà Phìn, stands the palace of the Vương family, a H'Mông clan whose leader was the de facto ruler of the region in the early twentieth century and made his fortune from opium. The palace is a fortified house of stone and carved wood, built with the help of Chinese craftsmen, and is open to visitors. To the north, the Lũng Cú flag tower marks the northernmost point of Vietnam.
For riders, the town is a base for exploring the plateau and the start of the famous ride over the Mã Pí Lèng pass to Mèo Vạc. The roads here are narrow and steep, with hairpins, sheer drops and changeable surfaces, and the weather can be cold, especially in winter, when temperatures can drop close to freezing and frost is not uncommon. Đồng Văn has fuel, guesthouses, homestays, cafes and restaurants, and it is a good place to rest, eat and check over the bike before the next stage.