Dublin Topography
The county stretches in length from north to south, and presents a sea-coast of about thirty miles, while its breadth in some places does not exceed seven. Except in the picturesque irregularities of its coast, and the grand and beautiful boundary which the mountains on its southern confines form to the rich vale below, it possesses less natural diversity of scenery than many other parts of the island; but it is superior to all in artificial decoration; and the banks of the Liffey to Leixlip present scenery of the most rich and interesting character. The grandeur of the features of the surrounding country, indeed, give the environs of the metropolis a character as striking as those, perhaps, of any city in the west of Europe.
The mountains which occupy the southern border of the county are the northern extremities of the great group forming the entire adjacent county of Wicklow: the principal summits within its confines are the Three Rock Mountain and Garrycastle, at the eastern extremity of the chain, of which the former has an elevation of 1586 feet, and the latter of 1869; Montpelier hill; the group formed by Kippure, Seefinane, Seechon, and Seefin mountains, of which the first is 2527 feet high, and Seechon 2150; and the Tallaght and Rathcoole hills, which succeed each other north-westward from Seechon, and. beyond the latter of which, in the same direction, is a lower range, composed of the Windmill, Athgoe, Lyons, and Rusty hills.
From Rathcoole hill a long range diverges south-westward, and enters the eastern confines of Kildare county, near Blessington. In the mountains adjoining Montpelier and Kilmashogue are bogs, covering three or four square miles; but the grandest features of these elevations are the great natural ravines that open into them southward, of which the most extraordinary is the Scalp, through which the road from Dublin to the romantic scenes of Powerscourt enters the county of Wicklow. From their summits are also obtained very magnificent views of the city and bay, and the fertile and highly improved plains of which nearly all the rest of the county is composed, and which form part of the great level tract that includes also the counties of Kildare and Meath.
The coast from the boldly projecting promontory of Bray head, with its serrated summit, to the Killiney hills is indented into the beautiful bay of Killiney. Dalkey Island, separated from the above-named hills by a narrow channel, is the southern limit of Dublin bay, the most northern point of which is the Bailey of Howth, on which is a lighthouse. The coast of the bay, with the exception of these two extreme points, is low and shelving, but is backed by a beautiful and highly cultivated country terminating eastward with the city. Much of the interior of the bay consists of banks of sand uncovered at low water. About a mile to the north of Howth is Ireland's Eye, and still farther north, off the peninsula of Portrane, rises Lambay Island, both described under their own heads. Between Howth and Portrane the coast is flat, and partly marshy; but hence northward it presents a varied succession of rock and strand; off Holmpatrick lie the scattered rocky islets of St. Patrick, Count, Shenex, and Rockabill.