Final answer:
Norway is the country with the Scandinavian Mountains that run along its border with Sweden and are remnants of the ancient Caledonian Mountains. The Western Highlands characterize Norway's terrain, contributing to its sparse population and limited agriculture. Norway, along with Sweden and Finland, has low population densities despite its large area.
Step-by-step explanation:
The country with the Scandinavian Mountains that run through the North and along the border between Norway and Sweden is Norway. These mountains are remnants of the ancient Caledonian orogeny, which occurred when the region that now constitutes Scandinavia collided with what is now North America in the early Paleozoic era. The Caledonian mountains primarily existed where we today find the Western Highlands, extending through Norway and into parts of Britain.
As a feature of Norway's geography, the Scandinavian Mountains are part of a rugged landscape that plays a significant role in limiting population density and large farming operations, leading to more common practices of livestock grazing or farming in valleys and meadows.
Additionally, the Northern Lowlands and the Western Highlands dominate the islands of Northern Europe with regions like Scotland, Wales, and parts of England presenting a varying terrain of short mountains and rugged highlands, in contrast to the more agriculturally feasible lowlands. Norway, Sweden, and Finland, despite their large physical areas, have relatively low population densities compared to other European nations, mirroring the sparse populations found in the Western Highlands.