What makes archeology such and adventure is that sometimes you don’t need to be a professional to do it. In 1929, a man repairing a sewage ditch in China’s Sichuan province came across a treasure trove of jade and stone artifacts, dating back to the Bronze Age. When experts go their hands on it, they couldn’t figure out where they came from.

Later studies have determined that these might have been relics of the Sanxingdui civilization, a culture that collapsed between 3,000 and 2,800 years ago. They supposedly inhabited a walled city on the Minjiang River, then one day, just left, burying all of their treasure in pits.