Numerous small archipelagoes and islands, of which the chief are Belle Tie, Groix and Ushant, fringe the Breton coast.- North of the Bay of St Michel the peninsula of Cotentin, terminating in the promontories of Hague and Barfleur, juts north into the English Channel and closes the bay of the Seine on the -west.
The fort rises from a huge mass of granite rock, which with a circumference of nearly 2 m., juts up abruptly to a height of 450 ft.
Spur of the lofty Tetons juts across the S.
It occupies a ridge or promontory, which juts out into the Adriatic Sea, under the bare limestone mass of Monte Sergio.
There are many rapids, caused by reefs of rock running across the bed, or by a sudden fall of from one to several feet, which produce very rough water below the swift glide; but the most dangerous places for navigation are where a point juts out into the stream, and the current, thrown back, causes a violent double backwater.