The Nazca Lines are a series of large ancient geoglyphs in the Nazca Desert, an arid coastal area of Peru. Scratched on the ground, the figures depict creatures from both the natural world and the human imagination. They include animals such as birds, fish or monkey, also plants, trees, flowers and oddly shaped fantastic figures. The largest figures are up to 370 meters long. Because of its isolation and the dry, stable climate of the plateau, the lines have mostly been naturally preserved. Geologists believe that these long series of geoglyphs were made by Nazca people in the ancient era between 200 BC to 500 AD. The lines were first brought to public awareness with the advent of flight—by pilots flying commercial planes over Peru in the 1930s. One of the theory states that the lines served for rituals to obtain water and fertility of crops.