Villazón is where Bolivia ends, and it is the sort of border town that lives off crossing and trade. It sits in the south of Potosí department at about 3,400 metres, with only a bridge and a busy street separating it from La Quiaca, its Argentine twin. Together they form one noisy urban stretch, with porters pushing loaded carts across, minibuses grinding through the gears and vendors selling everything from phone covers to coca leaves.
The road to get here is the pleasure. From Tupiza, you ride south along a high valley with red hills falling away on either side, with the road climbing gently over the open plateau and passing herds of llamas and the occasional adobe village. The cold is the most reliable feature, even in summer, because the wind blows straight off the altiplano and the nights get close to freezing. A good jacket and gloves matter more than any sightseeing.
The border itself is the main event. Formalities for a foreign motorcycle involve several offices on both sides, with exit stamps, vehicle permits and sometimes long queues on weekends, so arrive early in the morning, bring photocopies of everything, and expect to spend a couple of hours. Check current requirements before you go, because they change, and keep patient, since the officers are used to travellers and are mostly decent if you are organised.
The Argentine side opens onto Ruta 9, the road that runs south toward Humahuaca and Jujuy through the Quebrada de Humahuaca, one of the great valleys of the continent, with its painted hills, so crossing here sets up a superb ride. Behind you, Bolivia's long highland road is coming to its end.
For practical needs, Villazón is a real town of around thirty thousand people, so there is fuel, food and cash machines, but prices and rules for foreign-plated vehicles at the pumps can differ, and in Argentina fuel can be cheaper or dearer depending on the year, so ask and plan accordingly. The small restaurants near the market serve filling soups and grilled meat that are exactly right for the cold. Change leftover bolivianos before crossing, as they are hard to use elsewhere, and top up your tank on the Argentine side if you have the chance.