Places on the borders of provinces are always fascinating, and none more so than in Craglorn. Dragonstar, for instance, has a Redguard history- as evidenced by the enigmatic Ansei Satameh, the Tigress of Dragonstar- that is not apparent when you visit it, and has not yet been explored. I'd still love to know what the ancient, Redguard Dragonstar looked like- see some of its ruins, learn something about it.
A little further east of Dragonstar, just past the region of Skyreach, is the Valley of Scars: a cluster of ruined Nordic walls, towers and runestones on the northern edge of Upper Craglorn, inhabited now only by Iron Orcs. These structures would seem to tell a story about the complex history of this place.
Are these the ruins of First Empire Nordic occupation, or is it possible they are more recent? Notably, they occur in what every map so far shows is geographically Hammerfell. And while, as recently pointed out, it is true that maps are abstract schema not always reflected in the realities unfolding in real time and real space, there must have been contact between the Ra Gada of old known to inhabit the area, and the Nords expanding through the valleys. What was the nature of this contact? Was that contact the reason these now exist as ruins? Did the victorious Ra Gada drive the Nords back to their icy holds whooping and screaming? Or is there story here more complex, yet still untold?
The arch in the picture might have formed a gateway at some point. Did this, at one point, serve as the Nordic frontier?
The Howling Sepulchers in the north are particularly fascinating- with Nedic structures and Nedic undead on the valley floor, but distinctly Nordic structures and Nordic undead above- would seem to represent archaeological strata representing a transition from Nede to Nord, which, if deliberate, is really cool. The loadscreen mentions only Nedes, though, and similar mistakes have been made in the past (ie. Ra Gada ruins described as Nedic). I've explored the delve from head to toe looking for more explicit evidence about the story of this place, but so far, haven't found any.
The Valley of Scars in Craglorn lies south of the border of what would be Falkreath in Skyrim. Are the Nordic ruins and Sepulchers associated with ancestral Falkreath? Some time ago I speculated that "The Forest Kingdom to the North"
https://forums.elderscrollsonline.com/en/discussion/598390/falkreath#latest -described in lore associated with Skyreach- could have been a reference to ancient Falkreath; some great pre-Atmoran Nedic Kingdom in the forested northern slopes of the Jeral Mountains. Perhaps that Forest Kingdom extended southwards to the very borders of Skyreach, and even persisted into Nordic times?
Its hard to say how much of these details were deliberate design, or what is just being extrapolated for want of some world story-telling. Maybe they're just generic ruins sort of clumped down, with no further thought. Or maybe they were all designed with distinct history and character in mind. In the exploring I did, I couldn't find it. But I think that these sorts of questions reflect the essence of engaging, rewarding exploration. Discovering some corner of the world and reading a coherent story from it. Exploring to find evidence to interpret, and knowing there was deliberate thought exists behind threads we can discover makes exploration feel worthwhile and deliberately designed for.
Upper Craglorn, as we see it in game, represents (on its surface) what might be fascinating world-building. Ancient Redguard Dragonstar neighbouring similarly ancient Nordic strongholds, only one valley over suggest fascinating, yet still untold stories that the geography of the world- if not previous lore- is clearly pointing at. Lines on maps don't always tell the full story; but what is being mapped should.