The surface of the peninsula was very hilly and irregular, the shore-line was deeply indented with coves, and there were salt marshes that fringed the neck and the river-channel and were left oozy by the ebbing tides.
Of these highlands and lowlands is a rugged section with steep mountain-sides, deep narrow coves and valleys, and flat mountain-tops.
Sea-bathing is insecure, and is confined to a few small coves, approached by tunnels hewn through the rock.
It is indented with numerous bays and coves; its greatest length is 138 m., and its greatest breadth 69 m.
Although Maine has no coal and only a very small amount of iron ore within her borders for the encouragement of manufacturing, yet the abundance of fine timber and the numerous coves, bays and navigable streams along or near the coast promoted ship-building from the first, and this was the leading industry of the state until about the middle of the 19th century, when wooden ships began to be supplanted by those of iron and steel.