We all have heard about the big ancient geoglyphs of the Americas that were made centuries before us. But this one suddenly appeared in Australia in 1998!

The Marree Man, also known as Stuart’s Giant, is a modern geoglyph atop a plateau at Finnis Springs, 37 miles (60 km) west of Marree, South Australia. It depicts an indigenous Australian man hunting with a boomerang or stick and is 1.7 miles (2.7 km) tall with a perimeter of 17 miles (28 km). Although it is one of the largest geoglyphs in the world, its origin remains a mystery, with no one claiming responsibility for its creation.

The outline of this giant man figure drawn on earth was spotted by a helicopter pilot who was flying over central Australia and after that mystery started to surround who created and why. In 2018 Australian entrepreneur Dick Smith offered a A$5,000 (£2,800; $3,700) reward for any information about the artwork's origins.

Marree Man has been a subject of fascination since its discovery in the desert about 700km north of Adelaide. It has gained popularity on tourism flights because it is too large to be viewed from the ground. Locals believe it portrays an Aboriginal man carrying a woomera - a throwing stick - in his left hand. Marree publican Phil Turner says he is convinced that its creator, or creators, were "professionals" who possibly used GPS technology.

"Whoever did the outline marked it out with bamboo nursery skewers at every 10m," Mr Turner told the BBC.

"If you didn't have the co-ordinates, you would have no idea if you were standing in his left toe or his elbow. Considering GPS technology was in its infancy at the time, it is an absolutely remarkable feat."

Mr Smith agrees, telling the ABC: "There were no mistakes - it was very professionally done."

Several theories about its creators have circulated over the years.
Pilot Trevor Wright, the first to see Marree Man on 26 June 1998, says he spotted it by chance. But anonymous faxes were also sent to local businesses and media at the time, to inform them of Marree Man's existence.

Some suspected it was the work of American artists because the faxes used US spelling and references. A plaque showing the US flag and Olympic rings was also found at the site.

But others have theorised that those clues were deliberately misleading, with alternative suggestions including local artists and even members of the Australian Army.