Tambo Quemado is not a town so much as a border and a very long queue of trucks. It marks the crossing from Bolivia into Chile on the high road between La Paz and the Pacific coast at Arica, and the altitude, around 4,600 metres, is what everyone remembers, not the paperwork. The name means burnt inn, which tells you it has been a stopping point for travellers for a long time, though the modern place is a cluster of customs buildings, canteens and parked lorries on the open altiplano.
What makes it worth the ride is what surrounds it. The road from the east passes through the Sajama National Park, where the Nevado Sajama rises to 6,542 metres as Bolivia's highest mountain, a perfect, lonely cone that dominates the horizon for an hour before you reach it. Beside it stand the twin volcanoes Parinacota and Pomerape, and beyond the border on the Chilean side is Lago Chungará, one of the highest lakes on Earth, with flamingos, vicuñas and the symmetrical snowcap of Parinacota reflected in it on still mornings. Queñua trees, said to be among the highest forests in the world, cling to the slopes of Sajama.
The riding is long, empty and exposed. The paved road has few bends, but the wind builds from late morning and can push a bike sideways, so try to be moving early and plan to finish before the afternoon gusts. Nights are far below freezing. Expect heavy lorry traffic through the border zone, especially on weekdays, and be ready for long waits on either side. Border formalities, especially for a foreign motorbike, need time, patience and the right papers, so check what you must carry before you set out, since the rules change.
Practicalities are thin up here. There are no towns near the crossing itself, so fill the tank well before: the sensible places are in Patacamaya or the other towns along the road from La Paz, or in Arica on the Chilean side. Sajama village has basic lodging and hot springs nearby, which are just what a rider with frozen fingers wants. Carry water, a warm layer you do not mind getting dusty, and some patience for altitude.