Out here the Incas walked a road through country that most of us would call empty, and they did it without wheels, horses or a single petrol station. The stretch between the Río de la Sal and the Pampa del Inca is one of the Chilean pieces of the Qhapaq Ñan, the great Andean road network that tied Cusco to the far corners of the empire and was listed by UNESCO across six countries in 2014. In the Atacama region it shows up as a faint, dead-straight trace across gravel plains, sometimes edged with stones, sometimes marked by the low ruins of a tambo where runners and caravans once rested.
The nearest real town is Diego de Almagro, about 34 kilometres away, a mining town that grew up around copper and the railway, and it is where you sort out petrol, water and something to eat before heading into the open. Treat that as non-negotiable. Beyond it there is nothing commercial, no shade worth the name and no phone signal you should count on. Carry more water than seems sensible and tell someone where you are going.
The riding is about space rather than corners. Roads in this part of the desert are a mix of good tarmac laid for the mines and long gravel tracks where washboard ripples and soft patches of sand will test your arms and your patience. Wind gets up in the afternoon and comes across the pampa in hard gusts, so a morning run is kinder, and the low sun then throws long shadows that make the old road easier to pick out. Trucks serving the mines are big and fast; give them room and expect a wall of dust after each one.
What you get in return is light. The Atacama is one of the driest places on earth, and the air is so clear that hills thirty kilometres off look close enough to walk to. Colours change through the day from bleached grey to ochre, rust and violet, and after dark the sky is the reason observatories were built in this desert at all. The Río Salado, which gives the area its salty name, is a thin green line in an otherwise mineral world.
Stand on the old trace for a minute and think about the messengers who ran it in relays. Then get back on the bike, check your fuel gauge honestly, and head for Diego de Almagro with a margin to spare.