Ancient Astronaut Theorists uncover a 54 ton structure on Nan Madol that leads them to more questions, in this clip from Season 15, "The Mystery of Nan Madol." #AncientAliens Subscribe for more from Ancient Aliens and other great The HISTORY Channel shows: http://histv.co/SubscribeHistoryYT ...

Ancient Astronaut Theorists question who built Nan Madol after an artificial irrigation system is discovered, in this clip from Season 15, "The Mystery of Nan Madol." #AncientAliens Subscribe for more from Ancient Aliens and other great The HISTORY Channel shows: ...