The Aran Islands are made up of horizontal sheets of Carboniferous limestone and do not have naturally occurring topsoil. The inhabitants raise crops of oats and potatoes on soil that they have made using seaweed, sand, and manure. Some cattle are raised, and subsistence fishing is carried on.

The Aran Islands (Inishmore, Inishmaan, and Inisheer) off the coast of Ireland are a "living museum" of Gaelic culture and ancient history. A fascinating fact is that the islands have no naturally occurring topsoil; for centuries, residents created "man-made soil" by layering seaweed and sand over the barren limestone rock to grow potatoes. This unique landscape is enclosed by an incredible 1,600 kilometers (1,000 miles) of dry-stone walls, which are built without mortar and allow the Atlantic winds to pass through without knocking them down. The islands are also one of the few places where Irish is still the primary daily language (a "Gaeltacht" region). History buffs will find Dún Aonghasa, a 3,000-year-old prehistoric stone fort perched on the edge of a 100-meter cliff, which is considered one of the most spectacular ancient sites in Europe. Additionally, the islands are the birthplace of the world-famous Aran Sweater, where each complex knitting pattern originally held deep symbolic meaning for the fishing families. Despite their small size, the islands support a rare mix of Arctic, Mediterranean, and Alpine plants growing side-by-side in the limestone cracks.