Northern Europe comprises several groupings. The Nordic countries — Denmark, Finland, Iceland, Norway, Sweden — share cultural, linguistic, and political ties. The Baltic states — Estonia, Latvia, Lithuania — sit on the Baltic Sea, with distinct histories but regional cooperation. Additional nations with significant northern territory or identity include Ireland, the Netherlands, northern Germany, Poland, Scotland (UK), and the United Kingdom. Definitions vary by context (geographic, climatic, cultural), but these form the core of Europe's northern tier.