Kuk Swamp - Credit: Wikimedia Commons
Kuk Swamp is an archaeological site in Papua New Guinea, that lies in the Wahgi Valley of the highlands. The swamp developed in a former lake basin, as it was filled by an alluvial fan or deposits of water-transported material. Archaeological evidence for early agricultural drainage systems was found here, beginning about 9,000 years ago. It includes draining ditches of three major classes, which were used to convert the area to an anthropogenic grassland. The native crop taro was grown here. Read more on Wikipedia
Source: en.wikipedia.org