Hello, all. I'm part of the a mod team that's aiming to add a new province to the general map, but it's come to my attention that none of the modders we currently have with us know how to add the new worldspace to the default world map, game world-wise or map-wise. At current it's only possible to reach the new worldspace via a connecting cave-tunnel, but we'd kinda like to be able to, y'know, cross the border and stuff, and be able to fast travel to the new cities from the vanilla worldspace. Right now, unless we go in through the cave, then crossing the border only results in the default vanilla mass of endless trees. And we don't even have a map for our own worldspace since none of us know how to make that either; the local map works sometimes, while the world map, when it isn't blank, occasionally says I'm in the completely wrong hemisphere.

And I tried looking on the CS Wiki, but for once couldn't find any helpful information on this topic. Could anyone enlighten me as to how I would go about doing this?

In the vanilla game, when you're in a separate worldspace that's not a city then the main map shows where you left - e.g. Your pointer is on the Oblivion Gate you entered - while the local map shows the world you entered. The cities are the same coordinates inside and out, so going through the city gate puts you in a "parallel universe" that has the same map.

Which are you trying to emulate in your mod? The Oblivion world model, or the enclosed city model?

There's also "Shivering Isles" with a separate world map, but I don't understand that mechanism.