The Eastern Orthodox Uspenski Cathedral sits atop a hill in the Katajanokka district in Helsinki. This peninsula also boasts some of the most original Jugendstil or Art Nouveau architecture in the city.
Trinity Church is a small Russian Orthodox church on King George Island near Russian Bellingshausen Station in Antarctica. It is the southernmost Eastern Orthodox church in the world and also is the evidence of great human architecture at the south pole.
Kuopio Cathedral is one of the most beautiful in Finland. The city has developed on a number of islands and is surrounded by lakes and forests, making it very popular with nature lovers. You can find a photographic introduction to the city at the link provided.