The trick is in the special composition - within a day after application it hardens, turning into an elastic film. However, after a couple of years the material “biodegrades”, so this is a temporary solution. Price for a liter jar - $30

Just a couple of decades ago, Wangxian Village was unknown to anyone. It was a tiny settlement at the top of a mountain, and its few inhabitants lived in poverty, engaged in tea cultivation. But then, the local authorities decided to turn the village into a tourist attraction, as it was fashionable in China to create "historical monuments" that show how people lived in ancient times.