What is "geoglyphs"

Usage examples of "geoglyphs".

And out of that same epoch came the great Olmec sculptures, the inexplicably precise and accurate calendar the Mayans inherited from their predecessors, the inscrutable geoglyphs of Nazca, the mysterious Andean city of Tiahuanaco .

We must look forward to the day when the WormCam's delvings reach as far as the building of the Pyramids, Stonehenge, the Nazca geoglyphs and other sources of 'wisdom' or 'mystery.