How did the Norwegian fjords occur?
During the ice age both the ice and the rivers carved deep valleys in the mountains. As the climate changed, most of the ice melted, and the valleys were gradually filled with salt water from the coast, thus creating the fjords. Not all of the ice melted though, leaving parts of the high mountain areas covered with ice, thus creating the glaciers.
The main fjords of Norway:
The Geirangerfjord, the Nordfjord, the Sognefjord with the Naeroyfjord branch, and the Hardangerfjord. The Naeroyfjord and the Geirangerfjord are both on the UNESCO World Heritage Natural List.
Pictures from the Norwegian fjords