The two shores of the Adriatic are totally different in their natural characteristics; the western being almost islandless and destitute of harbours, while the eastern is fringed by an almost continuous chain of islands and possesses several magnificent harbours which communicate with the open sea by narrow channels easily fortified, the rocks rising precipitously from the water along the greater part of the coast, whereas on the Italian side there is an equally continuous strip of alluvial plain between the foothills and the sea.