Norway has the highest number of fjords in the world. Sometimes they extend up to 200 km into the land, where, in the last Ice Age, giant glaciers slipped towards the sea. The ice masses pressed stream valleys and river mouths into the soil and, on their way to the sea, they crushed even the hardest stones. Later, those valleys were filled with sea water, in this way the fjords were born. They are home to a stunning fauna. Many species in the fjord are as colourful as the light-flooded reefs in the tropics. And, indeed, in this realm of darkness, there even exist corals. What are all those creatures living from? What makes this habitat so special?