These Isles of Aran, with which the name of Enda is so intimately associated, stretch across the entrance to Galway Bay, forming a natural breakwater against the wild Atlantic billows. They are three in number--Aran Mor, Inismaan or Middle Island, and Inishere, or the Eastern Island, but frequently also called the Southern Island. A glance at the map will show that the islands trend to the north-west, opposing a straight wall of lofty cliffs to the waves of the Atlantic Ocean. Geologically the islands are a continuation of the limestone formation of the Burren mountains--"a gray and bluish-gray splintery limestone," containing in some places quarries of marble, which even in the time of Roderick O'Flaherty, some two hundred years ago, were worked for tomb-stones, chimney-pieces, and high crosses. The same author says the soil was paved with stone; in some places nothing is to be seen but the naked rock, cropping up everywhere with wide openings between the joints, "where cattle frequently break their legs." The surface falls to the north-east, and this lower shore line of Aran Mor is broken into two bays, which afford shelter from the prevailing winds. But on the south-west, or seaward line, the islands offer an almost unbroken wall of rock to the long swell of the ocean, rising in some places sheer from the sea to a height of nearly three hundred feet, and hidden beneath the waters to a depth of from twenty to thirty fathoms. Here and there the harder rock stands out in bold precipitous headlands, or completely isolated cliffs; while at other points the sea eats its way through caverns, where the waves roll in with hollow, thundering sound into the bowels of the rocks; and the compressed air within forcing its way upward forms 'puffing holes,' through which the spray is shot high in luminous columns into the air.