Europe's most significant feature is the dichotomy between highland and mountainous southern Europe and a vast. partially underwater, northern plain ranging from Ireland in the west to the Ural Mountains in the east. These two halves are separated by the mountain chains of the Pyrenees and Alps/Carpathians. The northern plains are delimited in the west by the Scandinavian Mountains and the mountainous parts of the British Isles. Major shallow water bodies submerging pars of the northern plains are the Celtic Sea, the North Sea the Baltic Sea complex and Barents Sea.