<h2>Answer: British Isles
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The British Isles are an archipelago (Great Britain and Ireland, and other smaller islands) located at the northwest of the coast of Europe. They are separated from the European continent by the North Sea to the east and by the English Channel to the south, while to the west and north they border the Atlantic Ocean.
However this was not always in this way. Millions of years ago this portion of land was a peninsula linked by a limestone mountainous ridge to mainland Europe. This is how, where the current Dover Strait is located, there was a rock formation that joint Great Britain and France.
It is estimated that it was at the end of the last Ice Age (this whole area was frozen and the sea level was far much lower than today) that this territory began to separate from the continent, a process that ended in the Mesolithic period, in the middle of the Stone Age, becoming the insular territory we know today.
In fact, the current Irish Sea and the North Sea were dry land that was submerged with the rise of sea level in the thaw.