The Nasca lines

Real ancient geoglyphs on a scale only visible from the sky

They are scratches, and that is the surprise of them. The pampa south of Nasca is covered in pebbles stained reddish brown by iron oxide, and underneath that crust the ground is a pale yellow grey. Lift the stones off and the pale ground shows through. Every line out there was made that way, by moving small rocks to one side, and the trenches are only about ten to fifteen centimetres deep. Nobody dug down. They swept.

UNESCO inscribed the Lines and Geoglyphs of Nasca and Palpa in 1994, protecting 75,358.47 hectares of that coastal plain roughly four hundred kilometres south of Lima. The figures were made across a very long stretch of time, from about 500 BCE to about 500 CE, which is not one event but forty generations of people returning to the same ground.

The reason they are still there is climate. This is one of the driest places on earth, almost windless at ground level, and the stone crust holds heat that steadies the air above it. A line swept two thousand years ago has had almost nothing happen to it since. That is also why a single set of tyre tracks across the pampa is a news story in Peru: the desert does not heal.

Maria Reiche is the reason much of it survived the twentieth century. She worked the pampa for close to sixty years, cleaning the contours of nearly a thousand lines with a ladder and a broom, and campaigned for the protection that eventually came.

You cannot read them from the ground. The shapes only resolve from the air or from the hills at the edge, which is what makes the site feel like it was made for a viewer who was not standing in it. What the lines were for is still argued over, and honest accounts leave it argued over.