Sticky Rice Porridge and the Great Wall of China
Mark Holmquist / Wikipedia, Tiny Fox Lab

One of the reasons the Great Wall of China still stands after so many years, is due to a secret binding agent in the mortar: sticky rice. Around the year 500 A.D., the Chinese started mixing sticky rice soup with slaked lime to make very strong and weather resistant mortar.Tiny Fox Lab Facts

Preview photo credit: Mark Holmquist / Wikipedia
Source: https://en.wikipedia.org/wiki/Sticky_rice_mortar