Geographically, the continent of Europe is a busy place. It is riddled with features that impede the formation of any large political entity. Mountain ranges inhibit trade and armies alike while peninsulas and islands limit the ability of larger powers to intimidate or conquer smaller ones. Because of such features, it isn't as much of a surprise that Europe has never united under a single government as it is that anyone has ever tried. That is because there are two other geographic features that push Europe together rather than pull it apart. The first is the North European Plain, an expansive stretch of lowland extending from the Russian steppe in the east to the Pyrenees in the west. This region is blessed with the densest concentration of navigable waterways in the world.