Northern Europe is a European region North of the Baltic Sea plus Denmark and the Nordic Islands in the North Atlantic.
Northern Europe comprises
$1545+: Scandinavia holiday biz fares (one-way) Scandinavian Airlines
$288+: Iceland fares via NY, Boston, more (one-way) Icelandair
$365+: Low fall fares to Scandinavia (one-way) Scandinavian Airlines
$400+: Rock-bottom fare to Iceland (round-trip) Icelandair
$2576+: Biz-class (round-trip) Europe sale fares Swiss International Air Lines
$329+: Fall Finland & Scandinavia fares (one-way) Scandinavian Airlines
$479+: Winter fares to European cities (round-trip) Air France