The jurisdiction of a sovereign state extends over all land within its boundaries, over all rivers, lakes or other bodies of water entirely within its boundaries, over the high seas for a distance of three miles from its coast, and over all bays or inlets on its coast whose mouth is not more than six miles across. The three mile limit was originally adopted because it was believed that this was the extreme range of cannon. The right of any nation to declare any part of the high seas (outside of the three mile limit) a mare clausum, and exclude other nations therefrom, has now been entirely abandoned.