The Western Uplands are a physical landscape that forms an arc along the western edge of Europe, stretching from western Spain and Portugal, through Brittany in France, across Wales, western Scotland, the English Lake District, and into western Scandinavia. They are made up of very old rocks that were formed and folded during the Caledonian and Hercynian mountain-building events. Over millions of years, these mountains were heavily eroded, particularly by glaciers during the last Ice Age. Glacial erosion created distinctive landforms, including marshlands, lakes, and the most dramatic features - fjords, which are long, narrow sea inlets with steep sides, most commonly found in Norway and western Scotland. - AsNotedIn