In the Yangtze Delta, about 160 kilometres southwest of Shanghai, the archeological ruins of Liangzhu City are located. The dripstones of Shennong Cave (pictured) and Jiulong Cave provide an accurate glimpse into the time of the Liangzhu culture's collapse about 4300 years ago. Credit: Haiwei ZhangDripstones store the answerCaves and their deposits, such as dripstones, are among the most important climate archives that exist. The precise dating was done by uranium-thorium analyses at Xi'an Jiaotong University, whose measurement accuracy is ± 30 years. Collapse of the Liangzhu and other Neolithic cultures in the lower Yangtze region in response to climate change.