The Appalachian Mountains and the Scottish Highlands are the same mountain range, because it is older than the continents moving apart.
I do regard them with terror, but this isn’t the reason why.
Because North America and Africa were once geographically connected, the Appalachians formed part of the same mountain chain as the Little Atlas in Morocco. This mountain range, known as the Central Pangean Mountains, extended into Scotland, before the Mesozoic Era opening of the Iapetus Ocean, from the North America/Europe collision (See Caledonian orogeny)
By the end of the Mesozoic Era, the Appalachian Mountains had been eroded to an almost flat plain.[27] It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed.
This sound like the opening of some eldritch horror novel.
There’s unironically a bunch of Appalachian cosmic horror stuff out there. In fact iirc Savage Worlds has a setting for it called Holler and Monte Cook games published a ttrpg for the Old Gods of Appalachia podcast.
Most of the Appalachians is now located within the eastern part of the United States as runoff. Imagine how long it took for huge mountains to erode down and wash outwards into the ocean that distance.
And the Appalachians are still young compared to a few other mountain areas around the world.