As we rode along in our van, our guide (a native of this island) told us about the various points of interest. He answered our questions too. He told us about the network of stone walls that crisscrossed this island. Apparently walls like these have been here for thousands of years. There main purpose being to mark the boundaries for plots of land that were used for agriculture. When a young man reached maturity he would be given a piece of his family's land. He was expected to put it to good use either for crops or grazing.