Many of Croatia’ coastline is characterized by karst topography—in other word, it’s rocky. To cultivate this rocky terrain, farmers painstakingly picked rocks out of the soil and then used the same to construct walls around geometric plots, creating, in some cases, a grid that stretched for kilometers. In Baljenac, an island just half a kilometer long, the walls stretch for 23 kilometers. Recently, the Croatian government has been pushing the UNESCO to include the island and its dry stone walls in their World Heritage Sites list.More info and other photos at Amusing Planet.
Aside from defining agricultural boundaries, the walls also keep out strong winds known as “bura”, that makes cultivation possible in exposed locations along the coastline.