Denmark, Estonia, Latvia and Lithuania are located on the northern shore of mainland Europe. Estonia, Latvia, and Lithuania sit on the Baltic Sea, bordering each other below Finland, Sweden and Norway. Denmark sits at the very top of mainland Europe, between the North and Baltic Seas. Some parts of Northern Russia are also considered part of Northern Europe. Northern Europe also consists of the Channel Islands and the Island of Man, which are part of the British Isles along with the United Kingdom and Ireland. Though Greenland is geographically located in North America, it is part of the Kingdom of Denmark. Historically speaking, when Europe was under Roman control, northern Europe was considered to also consist of Germany, Austria and the Low Countries. In medieval times, the word Thule was used to describe a mythical place at the far northern reaches of Europe.