Near the shore of Titicaca Lake, we find a large area covered by the "raised fields", which are earthworks of an ancent agricultural system, created in the Pukara period, quite before the Inca domination. The raised fields are arranged in a complex hydraulic system. We can observed it with the satellite (Google Maps).
With an image processing of the maps, the ancient agricultural system appears with all its beautiful structure and complexitiy.
Sometimes the raised fields assume symbolic forms.
For instance, the muzzle of a llama
It is seems a mouth touching the river (the white bend, white because the water is reflecting the light of sun), the nose, eye and ears. For comparison, a llama picture.
More on waru-waru
arXiv:1009.4602 [pdf] Geoglyphs of Titicaca as an ancient example of graphic design, Amelia Carolina Sparavigna
arXiv:1009.2231 [pdf] Symbolic landforms created by ancient earthworks near Lake Titicaca, Amelia Carolina Sparavigna