E A R T H F R O M A B O V E - P h o t o The Aran Islands feature cliffs that rise to a height of 300 feet (90 m), facing the rough winds and currents of the Atlantic. In an attempt to fertilize the soil, over the centuries the inhabitants have spread a mixture of sand and algae on the rocks to produce humus. To protect their limited plots of land from wind erosion, they have built a great network of windbreaking walls with a total length of some 7,000 miles