Map of United Kingdom
United Kingdom is an island nation located in northwest of Europe. United Kingdom consists of England, Wales, Scotland and Northern Ireland. The Northern Ireland located on the Island of Ireland is only part of United Kingdom that has natural land border with another country and this is with the Republic of Ireland.
United Kingdom on the Map

However, United Kingdom is connected to European mainland via approximately 50 km or 31 mi long railway tunnel named Eurotunnel. The tunnel opened in 1994 and connects UK with France under the English Channel.
English Channel is 34 km or 21 mi wide at the narrowest point and it separates United Kingdom from France and the rest of the continental Europe.
UK coastline is stretching along the Atlantic Ocean, the North Sea, the Irish Sea and the Celtic Sea.
Generally speaking
Iceland is located in North Atlantic Ocean approximately 1,300 km or 810 mi to the west from Scotland.