Korea: Jeju defences
The volcanic island of Jeju is located in the southernmost part of the Korean peninsula with sandy, rocky soil from which water tends to drain away. People used the stones in the soil to build a more than 22,000km series of fences as windbreaks and to stem the loss of water and soil, preserving local biodiversity in the process. Protected by the Jeju Batdam walls, agriculture on Jeju Island has survived natural disasters for more than 1,000 years, though it now faces newer challenges like widespread urbanisation.