The Giant of Atacama is a large figure of a human that was scraped out on the floor the Atacama desert in Chile. At 120 meters (393 ft)1 long, it is the largest humanoid geoglyph in the world, and is said to be the largest permanent human figure ever created2.
The Giant lives on the side of Cerro Unitas ('Solitary Mountain'), a large foothill in the arid region of Cordillera Domeyko, a range of foothills nudged up against the Andes. This is about 1,400 kilometers (850 miles) south of the Nazca desert, where the famous Nazca Lines are found. The Giant and the surrounding geoglyphs are formed in much the same way as the better-known Nazca Lines, by scraping away the topsoil to expose the lighter soil underneath.
Very little in known about these designs, but it is fairly well established that they are pre-Incan, probably dating to about 900 BC. These formations stretch for hundreds of miles along the Atacama plateau and the Piura region, numbering in the thousands. Some are just lines, some are unidentifiable designs, some are animals and humans. Because the area is so dry (one of the driest areas on Earth), these formations can last for centuries with little erosion. We don't really know why they were created, although it is generally assumed that they are either spiritual/religious in nature, or created by or for aliens. The alien hypothesis is vaguely supported by the fact that many of these designs can only be recognized from high in the air; we did not rediscover most of them until aircraft started flying over the area. The Giant, however, is easily visible from ground level. Various nutcases have managed to include it in the alien hypothesis by claiming that it shows a man wearing a spacesuit.
Footnotes:
1. Some sources have it at only 86 meters (282 ft).
2. The largest non-permanent human figure was probably the The Beaming Man, a laser installation at Burning Man 2000, at 1,219 meters (4000 ft). The largest statue is Lushan Dafo in Lushan, Henan, China, at a mere 108 meters (354 ft). However, see footnote #1.
Pictures:
http://www.atacamaphoto.com/atacama-art/atacama-art05.htm
http://survive2012.com/index.php/geoglyphs-world-wide.html
Ariel views