The Nazca Desert
The Nazca Desert is perfectly suited for not only drawing lines, but also for being able to preserve the drawings. The ground is flat and stony. There is hardly any rain and as such there is little dust or sand. The area underneath the ground is a lighter color than the pebbles on top. As such there is a strong contrast when the surface is scratched. In fact after making one of their own little Nazca figure, to demonstrate how it could be done, archeologist had to be careful to restore the area. Otherwise the figure would have remained there for hundreds or thousands of years, confusing future archeologists.