For one of the most unusual - and poignant - sunsets in the world wrap up warm and take a trip to Hammerfest, Europe's most northerly town. If you go towards the end of October you'll witness a weak, cold sun dropping over the horizon. It lasts just a few minutes - and it won't come back for nearly six months. Don't be depressed, though, the town has learnt how to enjoy itself at night. When the sun does come back in March, the permanent twilight of winter is replaced by a midnight sun.