Just as the $1 and $2 definitive postage stamps issued in March 1972 remind us of our urban centres, Canada's new medium value denomination remind us of the tremendous variety in our nation's terrain. The immensity and diversity of Canada are almost incomprehensible; few other nations have the challenge of the seas, the woodlands, the prairies, the mountains and the north. Our country, a land of breathtaking beauty, has inspired Reinhard Derreth, of Vancouver, to create these designs which capture something of the vastness and beauty. The natural splendour of the thousands of miles of Canadian seashore has been captured in the 50c. value. Canada probably possesses the most extensive and irregular coastline of any nation of the world if its approximately 60,000 miles of eastern, western and northern shores are taken into consideration. Much of the length of our coasts is rugged and barren; its ruggedness is accentuated by the continual pounding of the waves against its cliffs.