12. Disappearance of the Sanxingdui
Over 3,000 years ago, the civilization of Sanxingdui collapsed, completely disappearing from human history. However, in 1929 a man accidentally discovered jade and stone artifacts that were linked to this mysterious civilization. After more digging, an entire city alongside a river was discovered. However, the question remained: why did the Sanxingdui people leave? Many believed the civilization collapsed after an earthquake rerouted the river from the city. Unfortunately, we may never know the truth.