While we were touring the island of inis Oirr, an inquiry was made as to why the island had such a large number of rock walls. We were informed, by one of the natives, that so many rock walls exist simply because there are so many rocks. He explained that efforts to create usable land resulted in an abundance of small stones. To deal with the big piles that resulted from working the land, they opted to build them up, creating a large numbers of stone walls surrounding small workable patches of land. Pretty incredible structures that are actually built without mortar. The construction is really quite something, and the walls truly are a striking feature of the island. You immediately notice them once this tiny island comes into view.